Monday, December 8, 2008

LANs, WANs, and Other Area Networks

LANs, WANs, and Other Area Networks

Computer networks come in many different shapes and sizes. Over the years, the networking industry has coined terms like "LAN" and "WAN" attempting to define sensible categories for the major types of network designs. The precise meaning of this terminology remains lost on the average person, however.

Area Networks

For historical reasons, the industry refers to nearly every type of network as an "area network." The most commonly-discussed categories of computer networks include the following -

• LAN - Local Area Network
• WAN - Wide Area Network
• MAN - Metropolitan Area Network
• SAN - Storage Area Network
• SAN - System Area Network
• SAN - Server Area Network
• SAN - Small Area Network
• PAN - Personal Area Network
• DAN - Desk Area Network
• CAN - Controller Area Network
• CAN - Cluster Area Network

LANs and WANs were the original flavors of network design. The concept of "area" made good sense at this time, because a key distinction between a LAN and a WAN involves the physical distance that the network spans. A third category, the MAN, also fit into this scheme as it too is centered on a distance-based concept.
As technology improved, new types of networks appeared on the scene. These, too, became known as various types of "area networks" for consistency's sake, although distance no longer proved a useful differentiator.

LAN Basics

A LAN connects network devices over a relatively short distance. A networked office building, school, or home usually contains a single LAN, though sometimes one building will contain a few small LANs, and occasionally a LAN will span a group of nearby buildings. In IP networking, one can conceive of a LAN as a single IP subnet (though this is not necessarily true in practice).

Besides operating in a limited space, LANs include several other distinctive features. LANs are typically owned, controlled, and managed by a single person or organization. They also use certain specific connectivity technologies, primarily Ethernet and Token Ring.




WAN Basics

As the term implies, a wide-area network spans a large physical distance. A WAN like the Internet spans most of the world! A WAN is a geographically-dispered collection of LANs. A network device called a router connects LANs to a WAN. In IP networking, the router maintains both a LAN address and a WAN address. WANs differ from LANs in several important ways. Like the Internet, most WANs are not owned by any one organization but rather exist under collective or distributed ownership and management. WANs use technology like ATM, Frame Relay and X.25 for connectivity.
LANs and WANs at Home

Home networkers with cable modem or DSL service already have encountered LANs and WANs in practice, though they may not have noticed. A cable/DSL router like those in the Linksys family join the home LAN to the WAN link maintained by one's ISP. The ISP provides a WAN IP address used by the router, and all of the computers on the home network use private LAN addresses. On a home network, like many LANs, all computers can communicate directly with each other, but they must go through a central gateway location to reach devices outside of their local area.






What About MAN, SAN, PAN, DAN, and CAN?

Future articles will describe the many other types of area networks in more detail. After LANs and WANs, one will most commonly encounter the following three network designs:

A Metropolitan Area Network connects an area larger than a LAN but smaller than a WAN, such as a city, with dedicated or high-performance hardware.

A Storage Area Network connects servers to data storage devices through a technology like Fibre Channel.

A System Area Network connects high-performance computers with high-speed connections in a cluster configuration.




Conclusion

To the uninitiated, LANs, WANs, and the other area network acroymns appear to be just more alphabet soup in a technology industry already drowning in terminology. The names of these networks are not nearly as important as the technologies used to construct them, however. A person can use the categorizations as a learning tool to better understand concepts like subnets, gateways, and routers.

posted by Satpal Singh @ 6:52 AM   0 Comments

Simplex, Full-Duplex and Half-Duplex Operation

Simplex, Full-Duplex and Half-Duplex Operation

Another aspect of performance that is worthy of some attention is the mode of operation of the network or connection. Obviously, whenever we connect together device A and device B, there must be some way for A to send to B and B to send to A. Many people don’t realize, however, that networking technologies can differ in terms of how these two directions of communication are handled. Depending on how the network is set up, and the characteristics of the technologies used, performance may be improved through the selection of performance-enhancing modes.

Basic Communication Modes of Operation

Let's begin with a look at the three basic modes of operation that can exist for any network connection, communications channel, or interface.

Simplex Operation

In simplex operation, a network cable or communications channel can only send information in one direction; it's a “one-way street”. This may seem counter-intuitive: what's the point of communications that only travel in one direction? In fact, there are at least two different places where simplex operation is encountered in modern networking.

The first is when two distinct channels are used for communication: one transmits from A to B and the other from B to A. This is surprisingly common, even though not always obvious. For example, most if not all fiber optic communication is simplex, using one strand to send data in each direction. But this may not be obvious if the pair of fiber strands are combined into one cable.

Simplex operation is also used in special types of technologies, especially ones that are asymmetric. For example, one type of satellite Internet access sends data over the satellite only for downloads, while a regular dial-up modem is used for upload to the service provider. In this case, both the satellite link and the dial-up connection are operating in a simplex mode.

Half-Duplex Operation

Technologies that employ half-duplex operation are capable of sending information in both directions between two nodes, but only one direction or the other can be utilized at a time. This is a fairly common mode of operation when there is only a single network medium (cable, radio frequency and so forth) between devices.
While this term is often used to describe the behavior of a pair of devices, it can more generally refer to any number of connected devices that take turns transmitting. For example, in conventional Ethernet networks, any device can transmit, but only one may do so at a time. For this reason, regular (unswitched) Ethernet networks are often said to be “half-duplex”, even though it may seem strange to describe a LAN that way.

Full-Duplex Operation

In full-duplex operation, a connection between two devices is capable of sending data in both directions simultaneously. Full-duplex channels can be constructed either as a pair of simplex links (as described above) or using one channel designed to permit bidirectional simultaneous transmissions. A full-duplex link can only connect two devices, so many such links are required if multiple devices are to be connected together.

Note that the term “full-duplex” is somewhat redundant; “duplex” would suffice, but everyone still says “full-duplex” (likely, to differentiate this mode from half-duplex).

posted by Satpal Singh @ 6:51 AM   0 Comments

WHAT IS IP ADDRESS

WHAT IS IP ADDRESS? EXPLAIN HOW YOU WILL GET IP ADDRESS OF A COMPUTER SYSTEM?

Definition of IP address

(Internet Protocol address) The address of a device attached to an IP network (TCP/IP network). Every client, server and network device must have a unique IP address for each network connection (network interface). Every IP packet contains a source IP address and a destination IP address.

Static and Dynamic IP

An IP network is somewhat similar to the telephone network in that you have to have the phone number to reach a destination. The big difference is that IP addresses are often temporary.

Each device in an IP network is either assigned a permanent address (static IP) by the network administrator or is assigned a temporary address (dynamic IP) via DHCP software. Routers, firewalls and proxy servers use static addresses as do most servers and printers that serve multiple users. Client machines may use static or dynamic IP addresses. The IP address assigned to your service by your cable or DSL Internet provider is typically dynamic IP. In routers and operating systems, the default configuration for clients is dynamic IP (see DHCP).

Dotted Decimals

IP addresses are written in "dotted decimal" notation, which is four sets of numbers separated by periods; for example, 204.171.64.2. If you knew the IP address of a Web site, you could enter the dotted decimal number into your browser instead of the domain name (which is why we have DNS!).

Although the next version of the IP protocol offers a virtually unlimited number of unique addresses (see IPv6), the traditional IP address (IPv4) uses a 32-bit number that defines both the network and the host computer. The network class determines how many of the 32 bits are used for the network address, leaving the remaining bits for use as the host number (note the numbers of networks and hosts in the table below). The host number can be further divided between subnetworks and hosts (see subnet mask).


Class A, B and C

Although the computer identifies the class by the first three bits of the address (A=0; B=10; C=110), people identify the class by the first number in the address (see range below). This class-based system has also been greatly expanded, eliminating the huge disparity in the number of hosts that each class can accommodate (see CIDR).

Maximum Maximum Number of
Class Number Hosts Bits used in
Number of per Network/Host
Class Range Networks Network ID ID
A 1-126 127 16,777,214 7/24
B 128-191 16,383 65,534 14/16
C 192-223 2,097,151 254 21/8

127 reserved for loopback test






IP - Logical or Physical?

An IP address is somewhat of a hybrid, which can be thought of as either logical or physical, depending on how you view it. It is a unique number assigned to a node, which makes it seem physical, especially because there is so much name-to-IP address resolution going on in the network.

There is also the Ethernet address, which is built into the network adapter. That is indeed physical, and it does not change, which is very typical of physical device names. However, since IP addresses can be dynamically assigned, causing the same client workstation to have a different IP address every day, the IP address seems more like a logical address. Regardless of what it is, it would make a great debate in a computer science class. See logical vs. physical, IPv6, private IP addresses, TCP/IP abc's and IP on Everything.









How do I get an IP address for my computer or server.

There are three ways to get IP addresses for your workstations or servers. One is automatic and the other two require human intervention and registration. We obviously prefer that you obtain an IP address automatically. That way you can take a new computer out of the box, put it together, plug it into the network, and start using it immediately.
The three methods are:

Method Comments Obtained

DHCP Dynamic Host Configuration Protocol Automatically

M-DHCP Requires Application for Manual DHCP Hybrid

BOOTP Required Application for BOOTP Hybrid

Static Requires Application for manual or static Manually


If you can use normal DHCP, please do so. Your computer name gets automatically registered in DNS and it requires no manual actions on anyone's part. If you feel that you have special addressing needs, please read on. Then, if you still feel you have special addressing needs, you may apply for an address by calling Mark Harsen or by opening a Special Address Technical Support case with Networking which is described in the "How do I get one" section on this page.

DHCP - Dynamic Host Configuration Protocol

DHCP was created to meet the needs of the ever-evolving and changing needs of work stations and servers on the network. It was becoming unruly and impossible for network personnel to manually administer the thousands or tens of thousands of computers and addresses for an organization.

DHCP was invented to alleviate this problem. Basically, most computers are already configured, out of the box, to use DHCP. Therefore, you simply take your new computer out of the box, put it together, plug it into the network, and it starts working. Every computer has a name which can be changed by the owner of that machine. The configured name is sent as part of the DHCP request and, if not already taken, that name becomes the name or DNS name for your computer. If the name is taken, the system automatically adds a string to the end of the name to make it unique.

Many people think they need a special address that never changes for their web server, their file server, a Polycom video conferencing unit, or some other specific project. While there are some cases where special addressing needs do exist, the above mentioned are not among them. As long a computer system is online at least once a week, it's IP address will not change. If the IP address does change for a system, the DNS name will be kept up to date and point to the new IP address.




Therefore, everything that uses DNS, which is almost every Internet application, need not obtain an IP address through any other method other than our standard DHCP. This also leaves the users or system administrators free to move their machines around at will. Different networks, and thus different IP addresses, are used around campus and between campuses. Users must reapply for manual or hybrid addresses if the systems are moved to a different VLAN. Using standard DHCP, machines may be moved around campus or across campuses to Springfield, West Plains, Mt. Grove, or even Lebanon without any special actions having to be taken.
Also, if anything on the network changes, users automatically and transparently receive the new information. The machines run without interruption and without the knowledge that some networking stuff behind the walls changed. Other forms of addressing are not so fortunate.

What about Manual or Reserved DHCP addresses?

M-DHCP, Manual DHCP and a "DHCP Reservation" are different names for the same thing. Rarely, a special need exists where it is imperative that an IP address change as little as possible or where multiple DNS names must be associated with the same server. A web server hosting many home pages through different DNS names is a classical example of this. To accomplish this, nothing changes on the users machine. It is left configured to use DHCP, but specific information about the machine is given to Networking that we use to configure our DHCP servers. They will always give out the same address and have the same DNS aliases associated with the address.

If the user moves the machine, however, Networking must be contacted ahead of time to facilitate the move. It's a rather simple process, but failure to do it could result in loss of service to the moved resource.

BOOTP - Bootstrap Protocol

BOOTP was actually the predecessor of DHCP and DHCP is built on the foundation of BOOTP. It is a much older and bulkier attempt to solve the massive addressing problems presented by the Internet Protocol (IP). Users are strongly encouraged to steer clear of BOOTP in favor of DHCP or at least a Manual DHCP address. However, there are still some old systems on the network that do not support any from of DHCP. For those systems, we recommend BOOTP where it is supported. The only systems known to exist that need BOOTP are some cash registers, old Windows 3.11 machines, and old Macintoshes running MAC/TCP. Our recommendation would be to upgrade these machine where possible for these and other reasons.

BOOTP sends a specific request to a central server and expects networking configuration information to be sent to the machine. It configures itself, and attaches properly to the network. Registering a machine to use BOOTP is almost exactly the same as with M-DHCP, but the host name is fixed and can only be changed by Networking at the request of the owner. It is less reliable than DHCP, but shares the advantage that behind the scenes changes are maintained by Networking and the user never need to be concerned by network addressing or topology changes. If the user moves the machine to another VLAN, it must be re-registered.

Statically or Manually Configured

We like this form of addressing least of all. It requires registration of the address and it requires that the all network information, not just the station's IP address, be manually or "hard-coded" into the software on the machine. If the machine moves or if something behind the scenes change, it is most likely that any machine that has a static address will quit working.

We most often get requests from owners of Linux, Sun OS, or other variants of the Unix operating system for static addresses. It is true that most versions of Unix cannot support anything other than static addresses. We hope the Unix industry will someday recognize this flaw and reform as indeed many vendors of Linux already have.

posted by Satpal Singh @ 6:40 AM   0 Comments

Switching technology

Switching technology

In the next three subsections, we present the three switching techniques used in networks: circuit switching, datagram packet switching and virtual circuit packet switching.

Circuit switching




Circuit switching is the transmission technology that has been used since the first communication networks in the nineteenth century. In circuit switching, a caller must first establish a connection to a callee before any communication is possible. During the connection establishment, resources are allocated between the caller and the callee. Generally, resources are frequency intervals in a Frequency Division Multiplexing (FDM) scheme or more recently time slots in a Time Division Multiplexing (TDM) scheme. The set of resources allocated for a connection is called a circuit, as depicted in Figure 1.1. A path is a sequence of links located between nodes called switches. The path taken by data between its source and destination is determined by the circuit on which it is flowing, and does not change during the lifetime of the connection. The circuit is terminated when the connection is closed.
In circuit switching, resources remain allocated during the full length of a communication, after a circuit is established and until the circuit is terminated and the allocated resources are freed. Resources remain allocated even if no data is flowing on a circuit, hereby wasting link capacity when a circuit does not carry as much traffic as the allocation permits. This is a major issue since frequencies (in FDM) or time slots (in TDM) are available in finite quantity on each link, and establishing a circuit consumes one of these frequencies or slots on each link of the circuit. As a result, establishing circuits for communications that carry less traffic than allocation permits can lead to resource exhaustion and network saturation, preventing further connections from being established. If no circuit can be established between a sender and a receiver because of a lack of resources, the connection is blocked.

A second characteristic of circuit switching is the time cost involved when establishing a connection. In a communication network, circuit-switched or not, nodes need to lookup in a forwarding table to determine on which link to send incoming data, and to actually send data from the input link to the output link. Performing a lookup in a forwarding table and sending the data on an incoming link is called forwarding. Building the forwarding tables is called routing. In circuit switching, routing must be performed for each communication, at circuit establishment time. During circuit establishment, the set of switches and links on the path between the sender and the receiver is determined and messages are exchanged on all the links between the two end hosts of the communication in order to make the resource allocation and build the routing tables. In circuit switching, forwarding tables are hardwired or implemented using fast hardware, making data forwarding at each switch almost instantaneous. Therefore, circuit switching is well suited for long-lasting connections where the initial circuit establishment time cost is balanced by the low forwarding time cost.

The circuit identifier (a range of frequencies in FDM or a time slot position in a TDM frame) is changed by each switch at forwarding time so that switches do not need to have a complete knowledge of all circuits established in the network but rather only local knowledge of available identifiers at a link. Using local identifiers instead of global identifiers for circuits also enables networks to handle a larger number of circuits.

Traffic engineering (TE) consists in optimizing resource utilization in a network by choosing appropriate paths followed by flows of data, according to static or dynamic constraints [39]. A main goal of traffic engineering is to balance the load in the network, i.e., to avoid congestion on links on a network while other links are under-utilized. To achieve such goals, traffic engineering methods can vary from offline capacity planning algorithms to automatic, dynamic changes. Since circuit switching allocates a fixed path for each flow, circuits can be established according to traffic engineering algorithms.

On the other hand, circuit switching networks are not reactive when a network topology change occurs. For instance, on a link failure, all circuits on a failed link are cut and communication is interrupted. Special mechanisms that handle such topological changes have been be devised. Traffic engineering can alleviate the consequences of a link failure by pre-planning failure recovery. A backup circuit can be established at the same time or after the primary circuit used for a communication is set up, and traffic can be rerouted from the failed circuit to the backup circuit if a link of the primary circuit fails. Circuit switching networks are intrinsically sensitive to link failures and rerouting must be performed by additional traffic engineering mechanisms.


Datagram packet switching


Conceived in the 1960's, packet switching is a more recent technology than circuit switching which addresses a disadvantage of circuit switching: the need to allocate resources for a circuit, thus incurring link capacity wastes when no data flows on a circuit. Packet switching introduces the idea of cutting data on a flow into packets which are transmitted over a network without any resource being allocated. If no data is available at the sender at some point during a communication, then no packet is transmitted over the network and no resources are wasted. Packet switching is the generic name for a set of two different techniques: datagram packet switching and virtual circuit packet switching. Here, we give an overview of datagram packet switching.




Figure 1.2: Datagram Packet Switching.

Packets from a given flow are independent and a router can forward two packets from the same flow on two different links.

Different from circuit switching, datagram packet switching does not require to establish circuits prior to transmission of data and terminate circuits after the transmission of data. The switches, called routers, have to make a lookup in the forwarding table, called routing table, for each incoming packet. A routing table contains a mapping between the possible final destinations of packets and the outgoing link on their path to the destination. Routing tables can be very large because they are indexed by possible destinations, making lookups and routing decisions computationally expensive, and the full forwarding process relatively slow compared to circuit switching. In datagram packet switching networks, each packet must carry the address of the destination host and use the destination address to make a forwarding decision. Consequently, routers do not need to modify the destination addresses of packets when forwarding packets.

Since each packet is processed individually by a router, all packets sent by a host to another host are not guaranteed to use the same physical links. If the routing algorithm decides to change the routing tables of the network between the instants two packets are sent, then these packets will take different paths and can even arrive out of order. In Figure 1.2 for instance, packets use two different paths to go from User 1 to User 5. Second, on a network topology change such as a link failure, the routing protocol will automatically recompute routing tables so as to take the new topology into account and avoid the failed link. As opposed to circuit switching, no additional traffic engineering algorithm is required to reroute traffic.

Since routers make routing decisions locally for each packet, independently of the flow to which a packet belongs. Therefore, traffic engineering techniques, which heavily rely on controlling the route of traffic, are more difficult to implement with datagram packet switching than with circuit switching.


Virtual circuit packet switching



Figure 1.3: Virtual circuit packet switching. All packets from the same flow use the same virtual circuit.

Virtual circuit packet switching (VC-switching) is a packet switching technique which merges datagram packet switching and circuit switching to extract both of their advantages. VC-switching is a variation of datagram packet switching where packets flow on so-called logical circuits for which no physical resources like frequencies or time slots are allocated (see Figure 1.3). Each packet carries a circuit identifier which is local to a link and updated by each switch on the path of the packet from its source to its destination. A virtual circuit is defined by the sequence of the mappings between a link taken by packets and the circuit identifier packets carry on this link. This sequence is set up at connection establishment time and identifiers are reclaimed during the circuit termination.


We have seen the trade-off between connection establishment and forwarding time costs that exists in circuit switching and datagram packet switching. In VC-switching, routing is performed at circuit establishment time to keep packet forwarding fast. Other advantages of VC-switching include the traffic engineering capability of circuit switching, and the resources usage efficiency of datagram packet switching. Nevertheless, a main issue of VC-Switched networks is the behavior on a topology change. As opposed to Datagram Packet Switched networks which automatically recompute routing tables on a topology change like a link failure, in VC-switching all virtual circuits that pass through a failed link are interrupted. Hence, rerouting in VC-switching relies on traffic engineering techniques.

In practice, major implementations of VC-switching are X.25 [70], Asynchronous Transfer Mode (ATM [6]) and Multiprotocol Label Switching (MPLS [50]). The Internet, today's most used computer network, is entirely built around the Internet Protocol (IP), which is responsible for routing packets from one host to another. Because of the central role of IP in the Internet, we now discuss how ATM and MPLS interact with IP.

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posted by Satpal Singh @ 6:28 AM   0 Comments

The source of entertainment has evolved down the ages.

The source of entertainment has evolved down the ages. But human beings search for entertainment and things that could amuse him or her has been existing since time immemorial. One of the latest form of entertainment for the present civilization is computers. With inbuilt and loaded computer games, availability of softwares which allow you to paint, listen to music, watch videos, movies and also allow you to create music or videos or movies; computer has really become a major source of entertainment for the people who are computer savvy or at least computer literate. Other than this, the obvious source of entertainment on computers is the internet which not just connects you to the rest of the world but also allows you to find your amusement right at home. Chat rooms allow us to connect with like minded people and discuss with them about our favourite topics. Messengers also allow us to connect to your friends across the world and talk to them. Websites which carry news and other matters related to entertainment become a major source. Online games allow us to play with other people who have access to that game in a virtual world, while we are all seated in our own room in front of our PCs. Innumerable examples of internet as an entertainment source can be quoted. Now with Microsoft and Google promising to built the complete virtual structures of any city in the world on the internet, people would not have to travel to those people on holidays in order to explore and enjoy the city. They just have to log on to the Google World or the Microsoft site and explore the city online where they can walk down the streets enter buildings and even make purchase while they are gossiping about the prices with the other customers in the shops. Now can there be any doubt that computers are a main source of entertainment and amusement in this generation?

posted by Satpal Singh @ 6:27 AM   0 Comments

The Advantages (Benefits) of Networking

The Advantages (Benefits) of Networking

You have undoubtedly heard the “the whole is greater than the sum of its parts”. This phrase describes networking very well, and explains why it has become so popular. A network isn't just a bunch of computers with wires running between them.

Properly implemented, a network is a system that provides its users with unique capabilities, above and beyond what the individual machines and their software applications can provide.

Most of the benefits of networking can be divided into two generic categories: connectivity and sharing. Networks allow computers, and hence their users, to be connected together. They also allow for the easy sharing of information and resources, and cooperation between the devices in other ways. Since modern business depends so much on the intelligent flow and management of information, this tells you a lot about why networking is so valuable.

Here, in no particular order, are some of the specific advantages generally associated with networking:

o Connectivity and Communication: Networks connect computers and the users of those computers. Individuals within a building or work group can be connected into local area networks (LANs); LANs in distant locations can be interconnected into larger wide area networks (WANs). Once connected, it is possible for network users to communicate with each other using technologies such as electronic mail. This makes the transmission of business (or non-business) information easier, more efficient and less expensive than it would be without the network.

o Data Sharing: One of the most important uses of networking is to allow the sharing of data. Before networking was common, an accounting employee who wanted to prepare a report for her manager would have to produce it on his PC, put it on a floppy disk, and then walk it over to the manager, who would transfer the data to her PC's hard disk. (This sort of “shoe-based network” was sometimes sarcastically called a “sneakernet”.)


True networking allows thousands of employees to share data much more easily and quickly than this. More so, it makes possible applications that rely on the ability of many people to access and share the same data, such as databases, group software development, and much more. Intranets and extranets can be used to distribute corporate information between sites and to business partners.

o Hardware Sharing: Networks facilitate the sharing of hardware devices. For example, instead of giving each of 10 employees in a department an expensive color printer (or resorting to the “sneakernet” again), one printer can be placed on the network for everyone to share.

o Internet Access: The Internet is itself an enormous network, so whenever you access the Internet, you are using a network. The significance of the Internet on modern society is hard to exaggerate, especially for those of us in technical fields.

o Internet Access Sharing: Small computer networks allow multiple users to share a single Internet connection. Special hardware devices allow the bandwidth of the connection to be easily allocated to various individuals as they need it, and permit an organization to purchase one high-speed connection instead of many slower ones.

o Data Security and Management: In a business environment, a network allows the administrators to much better manage the company's critical data. Instead of having this data spread over dozens or even hundreds of small computers in a haphazard fashion as their users create it, data can be centralized on shared servers. This makes it easy for everyone to find the data, makes it possible for the administrators to ensure that the data is regularly backed up, and also allows for the implementation of security measures to control who can read or change various pieces of critical information.

o Performance Enhancement and Balancing: Under some circumstances, a network can be used to enhance the overall performance of some applications by distributing the computation tasks to various computers on the network.

o Entertainment: Networks facilitate many types of games and entertainment. The Internet itself offers many sources of entertainment, of course. In addition, many multi-player games exist that operate over a local area network. Many home networks are set up for this reason, and gaming across wide area networks (including the Internet) has also become quite popular. Of course, if you are running a business and have easily-amused employees, you might insist that this is really a disadvantage of networking and not an advantage!

posted by Satpal Singh @ 6:27 AM   0 Comments

Database Managements:

Computer database is a structured[citation needed] collection of records or data that is stored in a computer system so that a computer program or person using a query language can consult it to answer queries. The records retrieved in answer to queries are information that can be used to make decisions. The computer program used to manage and query a database is known as a database management system (DBMS). The properties and design of database systems are included in the study of information science.

A typical query could be to answer questions such as, "How many hamburgers with two or more beef patties were sold in the month of March in New Jersey?". To answer such a question, the database would have to store information about hamburgers sold, including number of patties, sales date, and the region. The term "database" originated within the computing discipline. Although its meaning has been broadened by popular use, even to include non-electronic databases, this article is about computer databases. Database-like collections of information existed well before the Industrial Revolution in the form of ledgers, sales receipts and other business-related collections of data.

posted by Satpal Singh @ 6:25 AM   0 Comments

Multimedia Development:

A multimedia computer is a computer, that is optimized for high multimedia performance, enabling rich multimedia experience.

The Intel platform, and Microsoft Windows XP Media Center Edition are two products aimed at multimedia computing. Unlike more Primitive Computer Systems that run at 16-75 MHZ, today true multimedia PCs have 3.0 Ghz(dual core or single-core), 1GB of RAM, a 128 MB or higher video card and TV Tuner card. these are equipped with a good graphic card as Nvidia GEforce or ATI Readon.

More recently, high-performance devices have become more compact, and the multimedia computer capabilities are found in mobile devices such as the Nokia Nseries, featuring DVD-like video quality, megapixel class cameras, fully capable browser, music and video players, podcasting, blogging, as well as e-mail, instant messaging, presence and internet call (VoIP) functionality. Multiradios help to offer broadband wireless connectivity, including for instance WCDMA/HSDPA and WLAN/Wifi. Devices are also increasingly equipped with GPS receivers and maps applications, providing new capabilities for location-aware services. The Nseries devices are also expandable, allowing for the addition of multiple applications and multimedia content.

posted by Satpal Singh @ 6:25 AM   0 Comments

Distributed computing:

Distributed computing is a method of computer processing in which different parts of a program are run simultaneously on two or more computers that are communicating with each other over a network. Distributed computing is a type of segmented or parallel computing, but the latter term is most commonly used to refer to processing in which different parts of a program run simultaneously on two or more processors that are part of the same computer. While both types of processing require that a program be segmented—divided into sections that can run simultaneously, distributed computing also requires that the division of the program take into account the different environments on which the different sections of the program will be running. For example, two computers are likely to have different file systems and different hardware components.

An example of distributed computing is BOINC, a framework in which large problems can be divided into many small problems which are distributed to many computers. Later, the small results are reassembled into a larger solution.

Distributed computing is a natural result of using networks to enable computers to communicate efficiently. But distributed computing is distinct from computer networking or fragmented computing. The latter refers to two or more computers interacting with each other, but not, typically, sharing the processing of a single program. The World Wide Web is an example of a network, but not an example of distributed computing

posted by Satpal Singh @ 6:24 AM   0 Comments

Difference between Star and Bus Network

Difference between Star and Bus Network

Star network



networks are one of the most common computer network topologies. In its simplest form, a star network consists of one central switch, hub or computer which acts as a conduit to transmit messages. If the central node is passive, the originating node must be able to tolerate the reception of an echo of its own transmission, delayed by the two-way transmission time (i.e. to and from the central node) plus any delay generated in the central node. An active star network has an active central node that usually has the means to prevent echo-related problems.

The star topology reduces the chance of network failure by connecting all of the systems to a central node. When applied to a bus-based network, this central hub rebroadcasts all transmissions received from any peripheral node to all peripheral nodes on the network, sometimes including the originating node. All peripheral nodes may thus communicate with all others by transmitting to, and receiving from, the central node only. The failure of a transmission line linking any peripheral node to the central node will result in the isolation of that peripheral node from all others, but the rest of the systems will be unaffected.

Advantages

• Good performance.
• Scalable, Easy to set up and to expand.
• Any non-centralised failure will have very little effect on the network, whereas on a ring network it would all fail with one fault.
• Easy to detect faults
• Data Packets are sent quickly as they do not have to travel through any unnecessary nodes.
• It is used for centralised control.

Disadvantages
• Expensive to install
• Extra hardware required
If the hub/switch fails the entire system is affected.

Bus network


A bus network topology is a network architecture in which a set of clients are connected via a shared communications line, called a bus. There are several common instances of the bus architecture, including one in the motherboard of most computers, and those in some versions of Ethernet networks.

Bus networks are the simplest way to connect multiple clients, but often have problems when two clients want to transmit at the same time on the same bus. Thus systems which use bus network architectures normally have some scheme of collision handling or collision avoidance for communication on the bus, quite often using Carrier Sense Multiple Access or the presence of a bus master which controls access to the shared bus resource.

A true bus network is passive – the computers on the bus simply listen for a signal; they are not responsible for moving the signal along. However, many active architectures can also be described as a "bus", as they provide the same logical functions as a passive bus; for example, switched Ethernet can still be regarded as a logical bus network, if not a physical one. Indeed, the hardware may be abstracted away completely in the case of a software bus.

With the dominance of switched Ethernet over passive Ethernet, passive bus networks are uncommon in wired networks. However, almost all current wireless networks can be viewed as examples of passive bus networks, with radio propagation serving as the shared passive medium.

Advantages and disadvantages of a bus network

Advantages


Easy to implement and extend
• Requires less cable length than a star topology
• Well suited for temporary or small networks not requiring high speeds(quick setup)
• Cheaper than other topologies.

Disadvantages

• Limited cable length and number of stations.
• If there is a problem with the cable, the entire network goes down.
• Maintenance costs may be higher in the long run.
• Performance degrades as additional computers are added or on heavy traffic.
• Proper termination is required.(loop must be in closed path).
• If many computers are attached, the amount of data flowing causes the network to slow down.
• Significant Capacitive Load (each bus transaction must be able to stretch to most distant link).
• It works best with limited number of nodes.

posted by Satpal Singh @ 6:22 AM   0 Comments

Register

Rgister: 1. A device, accessible to one or more input circuits, that accepts and stores data. Note: A register is usually used only as a device for temporary storage of data. 2. A temporary-memory device used to receive, hold, and transfer data (usually a computer word) to be operated upon by a processing unit. Note: Computers typically contain a variety of registers. General purpose registers may perform many functions, such as holding constants or accumulating arithmetic results. Special purpose registers perform special functions, such as holding the instruction being executed, the address of a storage location, or data being retrieved from or sent to storage.

posted by Satpal Singh @ 6:21 AM   0 Comments

System Software and Application Software

Difference Between System Software and Application Software

Software
:-Computers seem to perform amazing feats as they process information and display output almost instantly; but behind the scenes, they are really very simpleminded devices. All they do is plod along executing long strings of instructions that were previously written by a clever human programmer. The thing that makes a computer’s performances seem so amazing is that it executes these instructions very, very, very quickly, accurately, and tirelessly. Computers aren’t smart; they are just FAST.

But computers can’t do ANYTHING without step-by-step instructions written out for them. These lists of instructions are called programs. Programs (and the associated data) are known as software. Software needs to be installed onto a computer before it can be used. Software is often sold in sets of several programs and associated data called a software package, and typically comes on a CD-ROM or may be downloaded from the Internet. The Microsoft Office Suite is such a collection of programs and data that allows users to manipulate words, numbers, and data.

There are two major categories of software: System software and Application software.

System Software

System software controls a computer’s operations and manages a computer’s resources. System software includes the operating system, utilities, and computer programming tools.

The operating system (OS) controls the allocation of hardware resources such as memory space and CPU processing time, and handles the basic input and output (I/O) for data flowing from and to storage devices (such as hard disks) and peripherals (such as your keyboard). The operating system allows application software to access system resources without the applications having to know the details about the system hardware. The operating system often allocates resources and processing time between several programs which are running at once, which is called multitasking. Multitasking allows you to perform multiple tasks at the same time, such copying a chart from an open Excel document and pasting it into a report you have open in Word, all while your web browser is downloading a large file from the Internet in the background. It is the OS that plays traffic cop in this situation, deciding which program gets time on the CPU when, and handles the flow of data.

The operating system also includes software that provides the user with a operating environment for interacting with the computer. An operating environment could be a command-line interface (requiring the user to type in commands to control the computer), or it could be a graphical user interface (GUI, pronounced “gooey”) that allows users to interact with the computer using a mouse to point and click on icons, buttons, menus, etc.

IBM PC computers originally used the PC-DOS operating system (also sold by Microsoft to other PC users as MS-DOS). DOS is a general term that means “Disk Operating System” and old examples include DOS 3.3 for Apple II computers, and TRS-DOS of Radio Shack TRS-80 computer. However, when most people use the term DOS, they are referring to some version of Microsoft’s DOS for the PC — just as most people use the general term “PC” (which just means personal computer) to refer specifically to the IBM-PC and the PC-compatible computers descended from it.

Most PCs today use some version of the Microsoft Windows operating system (such as Windows 2000 or Windows XP). Windows includes a GUI user environment. A smaller number of PCs use the Linux operating system (a Unix-like OS).

Macintosh computers use some variation of the Macintosh OS, which is a GUI operating system. Older macs may use Mac OS 9, but newer Macs use Mac OS X (pronounced “O S ten”). OS X is built on top of FreeBSD, a Unix-like OS.

High-end microcomputer workstations, file servers, and mainframes often run some variation of the Unix operating system.

System software also includes the software needed to access a peripheral device connected to the computer. Such software is called a device driver, and it controls I/O to the peripheral. The device drivers may come already installed in the OS, or you may have to install or update a driver when you add a new peripheral device.
System software may also include security software, such as Virus checkers and firewalls. A virus checker searches files for potentially harmful programs such as viruses, worms, or trojan horses that are written by malicious programmers. Viruses and similar programs can perform disastrous activities on your computer system, such as erasing your hard disk. To be safe, you should scan all downloaded files and messages on your PC (anti-virus software can automatically do this) and never run any e-mail attachments if you don’t know what they are. (Note: There are vastly fewer viruses that affect Macintosh computers than affect PCs.) A firewall, or similar program, protects your computer from unauthorized access over a network or telecom connection.

Utilities are programs that perform a very specific task, usually related to managing system resources such as disk drives, printers, etc. Unlike application software, utilities tend to be smaller in size and perform activities related to the computer system (scanning for viruses, manipulating file settings, scanning for disk errors, etc.). Some utilities are memory-resident programs that are loaded into RAM and operate in the background.

System software also includes the tools used to write other programs. These include compilers, assemblers, and debuggers for various computer programming languages. A programming language allows a person to write computer instructions in a language that is easier for a human to understand, but which is then converted into the low level numerical instruction codes that a computer processor unit can execute. Some programming languages include C, C++, Java, FORTRAN, COBOL, PASCAL, BASIC, Visual Basic (and such scripting languages as JavaScript and Perl).

posted by Satpal Singh @ 6:18 AM   0 Comments

Types of Computers

Types of Computers


Computers come in a variety of types designed for different purposes, with different capabilities and costs.

Microcomputers

A microcomputer is a computer that has a microprocessor chip as its CPU. They are often called personal computers because they are designed to be used by one person at a time. Personal computers are typically used at home, at school, or at a business. Popular uses for microcomputers include word processing, surfing the web, sending and receiving e-mail, spreadsheet calculations, database management, editing photographs, creating graphics, and playing music or games.
Personal computers come in two major varieties, desktop computers and laptop computers:

Desktop computers are larger and not meant to be portable. They usually sit in one place on a desk or table and are plugged into a wall outlet for power. The case of the computer holds the motherboard, drives, power supply, and expansion cards. This case may lay flat on the desk, or it may be a tower that stands vertically (on the desk or under it). The computer usually has a separate monitor (either a CRT or LCD) although some designs have a display built into the case. A separate keyboard and mouse allow the user to input data and commands.

Laptop or notebook computers are small and lightweight enough to be carried around with the user. They run on battery power, but can also be plugged into a wall outlet. They typically have a built-in LCD display that folds down to protect the display when the computer is carried around. They also feature a built-in keyboard and some kind of built-in pointing device (such as a touch pad).
While some laptops are less powerful than typical desktop machines, this is not true in all cases. Laptops, however, cost more than desktop units of equivalent processing power because the smaller components needed to build laptops are more expensive.

PDAs and Palmtop Computers

A Personal Digital Assistant (PDA) is a handheld microcomputer that trades off power for small size and greater portability. They typically use a touch-sensitive LCD screen for both output and input (the user draws characters and presses icons on the screen with a stylus). PDAs communicate with desktop computers and with each other either by cable connection, infrared (IR) beam, or radio waves. PDAs are normally used to keep track of appointment calendars, to-do lists, address books, and for taking notes.

A palmtop or handheld PC is a very small microcomputer that also sacrifices power for small size and portability. These devices typically look more like a tiny laptop than a PDA, with a flip-up screen and small keyboard. They may use Windows CE or similar operating system for handheld devices.
Some PDAs and palmtops contain wireless networking or cell phone devices so that users can check e-mail or surf the web on the move.

Workstations/Servers

A workstation is a powerful, high-end microcomputer. They contain one or more microprocessor CPUs. They may be used by a single-user for applications requiring more power than a typical PC (rendering complex graphics, or performing intensive scientific calculations).

Alternately, workstation-class microcomputers may be used as server computers that supply files to client computers over a network. This class of powerful microcomputers can also be used to handle the processing for many users simultaneously who are connected via terminals; in this respect, high-end workstations have essentially supplanted the role of minicomputers (see below).

Note! The term “workstation” also has an alternate meaning: In networking, any client computer connected to the network that accesses server resources may be called a workstation. Such a network client workstation could be a personal computer or even a “workstation” as defined at the top of this section. Note: Dumb terminals are not considered to be network workstations (client workstations on the network are capable of running programs independently of the server, but a terminal is not capable of independent processing).

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There are classes of computers that are not microcomputers. These include supercomputers, mainframes, and minicomputers.

Minicomputers

A minicomputer is a multi-user computer that is less powerful than a mainframe. This class of computers became available in the 1960’s when large scale integrated circuits made it possible to build a computer much cheaper than the then existing mainframes (minicomputers cost around $100,000 instead of the $1,000,000 cost of a mainframe).

The niche previously filled by the minicomputer has been largely taken over by high-end microcomputer workstations serving multiple users (see above).


Mainframes

A mainframe computer is a large, powerful computer that handles the processing for many users simultaneously (up to several hundred users). The name mainframe originated after minicomputers appeared in the 1960’s to distinguish the larger systems from the smaller minicomputers.

Users connect to the mainframe using terminals and submit their tasks for processing by the mainframe. A terminal is a device that has a screen and keyboard for input and output, but it does not do its own processing (they are also called dumb terminals since they can’t process data on their own). The processing power of the mainframe is time-shared between all of the users. (Note that a personal computer may be used to “emulate” a dumb terminal to connect to a mainframe or minicomputer; you run a program on the PC that pretends to be a dumb terminal).

Mainframes typically cost several hundred thousand dollars. They are used in situations where a company wants the processing power and information storage in a centralized location. Mainframes are also now being used as high-capacity server computers for networks with many client workstations.


Supercomputers

A supercomputer is mainframe computer that has been optimized for speed and processing power. The most famous series of supercomputers were designed by the company founded and named after Seymour Cray. The Cray-1 was built in the 1976 and installed at Los Alamos National Laboratory. Supercomputers are used for extremely calculation-intensive tasks such simulating nuclear bomb detonations, aerodynamic flows, and global weather patterns. A supercomputer typically costs several million dollars.

Recently, some supercomputers have been constructed by connecting together large numbers of individual processing units (in some cases, these processing units are standard microcomputer hardware).

Please note: All of this talk of which computers are more powerful than others (i.e., mainframes are more powerful than minicomputers, which are more powerful than microcomputers) is relative for any particular moment in time. However, all classes of computers are becoming more powerful with time as technology improves. The microprocessor chip in a handheld calculator is more powerful than the ENIAC was, and your desktop computer has more processing power than the first supercomputers did.


________________________________________

posted by Satpal Singh @ 6:16 AM   0 Comments

Virus

Viruses -
A virus is a small piece of software that piggybacks on real programs. For example, a virus might attach itself to a program such as a spreadsheet program. Each time the spreadsheet program runs, the virus runs, too, and it has the chance to reproduce (by attaching to other programs) or wreak havoc.

E-mail viruses - An e-mail virus travels as an attachment to e-mail 2messages, and usually replicates itself by automatically mailing itself to dozens of people in the victim's e-mail address book. Some e-mail viruses don't even require a double-click -- they launch when you view the infected message in the preview pane of your e-mail software

Trojan horses - A Trojan horse is simply a computer program. The program claims to do one thing (it may claim to be a game) but instead does damage when you run it (it may erase your hard disk). Trojan horses have no way to replicate automatically.

Worms - A worm is a small piece of software that uses computer networks and security holes to replicate itself. A copy of the worm scans the network for another machine that has a specific security hole. It copies itself to the new machine using the security hole, and then starts replicating from there, as well.


How to Protect Your Computer from Viruses.

You can protect yourself against viruses with a few simple steps:

If you are truly worried about traditional (as opposed to e-mail) viruses, you should be running a more secure operating system like UNIX. You never hear about viruses on these operating systems because the security features keep viruses (and unwanted human visitors) away from your hard disk.

If you are using an unsecured operating system, then buying virus protection software is a nice safeguard.

If you simply avoid programs from unknown sources (like the Internet), and instead stick with commercial software purchased on CDs, you eliminate almost all of the risk from traditional viruses.

You should make sure that Macro Virus Protection is enabled in all Microsoft applications, and you should NEVER run macros in a document unless you know what they do. There is seldom a good reason to add macros to a document, so avoiding all macros is a great policy.

You should never double-click on an e-mail attachment that contains an executable. Attachments that come in as Word files (.DOC), spreadsheets (.XLS), images (.GIF), etc., are data files and they can do no damage (noting the macro virus problem in Word and Excel documents mentioned above). However, some viruses can now come in through .JPG graphic file attachments. A file with an extension like EXE, COM or VBS is an executable, and an executable can do any sort of damage it wants. Once you run it, you have given it permission to do anything on your machine. The only defense is never to run executables that arrive via e-mail.

posted by Satpal Singh @ 6:10 AM   0 Comments

Cache Memory

Cache Memory







- Cache memory is random access memory (RAM) that a computer microprocessor can access more quickly than it can access regular RAM. As the microprocessor processes data, it looks first in the cache memory and if it finds the data there (from a previous reading of data), it does not have to do the more time-consuming reading of data from larger memory.

Cache memory is sometimes described in levels of closeness and accessibility to the microprocessor. An L1 cache is on the same chip as the microprocessor. (For example, the PowerPC 601 processor has a 32 kilobyte level-1 cache built into its chip.) L2 is usually a separate static RAM (SRAM) chip. The main RAM is usually a dynamic RAM (DRAM) chip.

In addition to cache memory, one can think of RAM itself as a cache of memory for hard disk storage since all of RAM's contents come from the hard disk initially when you turn your computer on and load the operating system (you are loading it into RAM) and later as you start new applications and access new data. RAM can also contain a special area called a disk cache that contains the data most recently read in from the hard disk.

posted by Satpal Singh @ 6:09 AM   0 Comments

Benefits of internet in education

Welcome to the Internet in an educational setting.

The Internet has become an intricate part of today's secondary education. More and more schools are using the Internet to learn about things that can't be taught in a regular classroom. It provides classrooms with an enormous amount of resources from all over the world to students, teachers and media specialists. All the information, images and computer software can be reached almost immediately.

It also allows availability to everyone regardless of geography, resources, disability, gender, income, national origin and race. Kids can communicate with other kids in the other side of the world. The classroom can have anyone there, from new and old friends to experts. Not only can schools gain knowledge from others, but they can share their work with others as well.

Vice President Al Gore challenged the communciations industry to connect every American classroom to the "information superhighway" by the year 2000. President Clinton launched a nationwide mission to have every student be technologically literate by the 21st century.

"In our schools, every classroom in America must be connected to the information superhighway with computers and good software and well-trained teachers...I ask Congress to support this education technology initiative so that we can make sure this national partnership succeeds," said President Clinton in the State of the Union on Jan. 23, 1996.

In this mission, President Clinton challenged schools, teachers, students, parents, the private sectors, community groups, state and local governments, and the federal government to meet this goal. He set four standards to help meet this goal:

1. Train and support all teachers to help students learn through computers and the information superhighway;

2. Create effective software and on-line learning resources as important parts of the school curriculum;

3. Make modern computers available for all teachers and students;

4. Connect all American schools and classrooms to the information superhighway.

So sneak a peek at what this modern technology can do for today's students. You can learn about what they are learning through the Internet.



Internet May Improve Learning Process

So what can the Internet do for students in school? In a nutshell, a lot. It can make learning even more interesting.
Students no longer have the option of just having to learn about a region or specific culture from a book. They can actually talk to people who live in that region and get first-hand information about it. The Internet brings the world to the classrooms.
The endless amount of information in the Internet is at their disposal through a computer and a modem. Forget about going to the library. This hands-on tool allows students to relate their interests on a personal level, which is believed to motivate students to do better in school. Many educators believe it can encourage the type of independence students need to progress in their learning process.
There have been a few studies that have shown that those students who use on-line technology may perform better than those who don't. They've also shown that students perform better on comprehension, presentation and communication skills when thay have access to the Internet.
One study compared two groups of students' final projects about the civil rights movement. One group had on-line access, the other didn't. The results showed that the students who had access to on-line generally turned in better work.
The study was done by the Center for Applied Special Technology.
The value of the Internet isn't only the wealth of knowledge it contains. The impact it has on the students' facilitation of learning is also a valuable factor.


Internet Has Many Benefits

There is so much that students can do with the Internet. Not only can they communicate with international students, they can gain from others' knowledge and experiences, participate in chatrooms, share ideas and solutions and learn about the many diverse cultures out there.

While the Internet does a lot for students, there are also benefits for parents and teachers. The interactive learning that the Internet provides can help students and parents with little or no English skills to learn English. Parents can become more involved in their children's education by connecting the school with homes, libraries or other access ports.

Teachers can adjust to the different learning styles and in the classroom. They can also set their own pace of teaching. Individual teaching techniques can become more available, which has been proven to be a factor in student achievement.
Teachers have the chance to be able to teach at more than one place simultaneously. They may be in a small town but through the Internet, they can be linked to students in more populated areas.

Also, the Internet enables administrators and teachers to spend less time on administration and recordkeeping. This would also give them more time to spend with their students.

Global Classrooms and Networks Offer Different Ways of Learning
Students can experience this new way of learning through many networks and global classrooms. These networks give them the chance to learn through the on-line technology from all over the world.

Some of the networks and classrooms that give the students these kinds of opportunities are:

AT&T Learning Network
It links seven to nine classrooms in different places into a Learning Circle for six, 11 or 15 weeks. Its purpose is to achieve geographic and cultural diversity with participants from all over the world.

Students can investigate the same topic and communicate on toll-free lines via the AT&T Mail Network electronic mail system. They can present ideas, create solutions to problems, question beliefs and challenge stereotypes. Classes can then work as a group to summarize, edit and evaluate ideas that were presented. At the end, they produce a final Learning Circle publication.

There are seven themes: Classroom Connections, Mind Works, Computer Chronicles, Places and Perspectives, Energy and the Environment, Society's Problems and Global Issues.

Intercultural E-mail Classroom Connections

This network provides international e-mail connections for students. A student can request individual pen pals from a specific area, or classrooms can be connected to other students to work together on projects. Teachers can request help or make an announcement of certain classroom projects that involve e-mail.
World Classroom Network

Students and teachers around the world are given the chance to work together on different projects. Subjects vary from science, social studies to language arts. They are able to particpate in discussions with guest speakers and multilingual student exchanges. Students can also communicate with international peers in individual and group writing activities.

Global Common Classroom

U.S. schools are linked to others nationwide through this network. It keeps and enhances existing classroom collaborations between schools in Russia and the United States. It initiates new arrangements with schools and universities in Poland, Romania, Bulgaria, Hungary and Spanish-speaking countries in North, South and Central America.

Kids Network

Elementary school students are able to participate in science and geography projects. Students gather information locally and then share the information with other students through the network. Some of the topics have included acid rain, water pollution, recycling, weather, solar energy and nutrition.


Take Advantage of Endless Possibilities

It's never too late to do something on the Internet. Students from around the world have worked on research projects together, talked to each other and learned about each other's culture and country. Right now, as you're reading this, there are two children communicating to each other from opposite sides of the world.

Through the Internet, the possibilities are just about endless. Children can learn about the Orient or find out what's going on Argentina whenever they want. It allows students to learn at their own rates with a wide variety of classmates.

They have a headstart with computers, most likely beginning around second or third grade. By the time they graduate from high school, they'll be all set and ready to go and conquer the world with their extensive computer knowledge!

Some of those children already have homepages on the World Wide Web. Check out some of them out through Web66, a project that lists schools with homepages from around the world. It also helps educators learn how to set up their own Internet servers, link web servers and the educators and students at those schools, and help eudators find and use the right resources on the Web.

So if you want to learn about different ideas and beliefs, the Internet allows you to do that. Or if you want to share your own thoughts, hey, the Internet can do that, too. The possibilities for knowledge are everywhere in the Internet.
Other authors note


Benefits of Internet Use in Education

The use of the World Wide Web appears to offer a number of unique benefits to education such as increasing accessibility and student motivation.
The following is a survey of research concerning some of the major benefits of Internet use in education:

• Accessibility to Learning Opportunities & Resources
• Economical Delivery of Instruction
• Promoting Improved Learning
• Enables New Instructional Models
• Advantages of CMC
• CMC as a "Mindtool"
• Benefits of Hypermedia Construction
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Accessibility to Learning Opportunities & Resources

One of the primary advantages of the Internet is that it can make learning more accessible. It can remove the physical boundaries of classrooms, reduce class scheduling restraints, and offer easy access to searchable databases and a vast array of other world-wide resources. The Web is an open technology - it is accessible by any modern computer (Owston,1997 - see online summary).

The Web is playing an increasingly important role in the area of distance education. Web-based learning can supplement or replace traditional distance educational opportunities which have been provided in the past via postal correspondence, printed materials, audio or video cassettes, and television. According to Bates (1995), "Access is usually the most important criterion for deciding on the appropriateness of a technology for open or distance learning". The Internet's great strength is that it can make instruction time-independent and location-independent; it is able to reach students whenever and wherever they find it convenient to learn (in their homes, at work, etc.).

Owston details a number of benefits to postsecondary web-based instruction including: reducing residency requirements, harmonizing with family commitments, and promoting student-centered learning. He provides an excellent example which demonstrates that Internet-based learning can provide interaction equal to traditional classes: students in the Birkbeck College Crystallography program at the University of London are able participate in discussions with hundreds of students and many experts in the field from around the world and also have the opportunity to work in smaller study groups to produce collaborative research reports.

Owston and others (Hackbarth, 1997; McKenzie, 1997) also see a promising case for the use of the Web in K-12 education. For example, high school students can enroll in externally developed online high school courses, which might be impossible locally due to limited budget, small enrollments, lack of facilities, or lack of qualified teachers. In the traditional classroom, the Web can be used to consult scientists, writers and other experts or to obtain learning materials at little cost.

Many organizations have created no charge web resource collections. Two excellent examples are Canada's SchoolNet and Classroom Connect. The Texas Education Network provides links to curriculum guides, journals, reference materials, K-12 school and teacher websites, museums, libraries, academic experts, etc. The Web can also be a tremendous boon in the areas of home or private schooling by providing greater access to quality learning materials, contact with peers, and information for parents and teachers (Owston, 1997; Dooling, 1996).

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Economical Delivery of Instruction

Freeman & Ryan (1997) indicate that "specialist courses which can no longer be supported by drawing on the student base in the traditional university catchment area can now be offered economically world wide". Faulhaber (1996) states that the Internet makes economic sense in the delivery of low-enrollment university courses. Sending the course to multiple campuses lowers the per-pupil cost.

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Promoting Improved Learning

There is also evidence that the Web can promote improved learning, but not just by virtue of using this medium itself. As Owston states, "No medium in and of itself is likely to improve learning in a significant way when it is used as a tool to deliver instruction. Nor is it realistic to expect the Web, when used as a tool, to develop in students any unique skills. The key to promoting learning with the Web appears to lie in how effectively the medium is exploited in the teaching and learning situation" (Owston, 1997). Instructional goals and objectives should be determined first, then the technology to support them should be located (Barron & Orwig, 1995). i.e. Technological resources must be chosen to fit the curriculum, not vice-versa. "Technology is the servant, and the message, the idea, the matter" (Pettersson, 1989). As with any teaching tool, technology should be implemented only where appropriate. There will be a tremendous waste we all rush to "get everything on the Web".

Marchionini (1988) presents the view that hypermedia systems (such as web-based materials) "model human associative memory and thus can serve as powerful cognitive amplifiers". He sees the following advantages in the use of hypermedia:

• Allow large amounts of information in various media to be stored very compactly and accessed easily;

• Offer high levels of learner control which force students to apply higher order thinking skills;

• Can alter the roles of teachers to more of a guide and create richer interactions among students and teachers.

Hypermedia has potential in education due to its non-linear association of information (which can encourage active, student-centered, individualized learning) and use of multiple information formats (which can motivate learners and provide more natural, efficient, multi-channel representations of knowledge). A study by Fitzgerald & Semrau (1997) demonstrated that hypermedia learning environments can provide equally effective instruction for learners regardless of prior computer knowledge or learning style (mixture of field independence / dependence). Hypermedia systems can also promote collaboration by allowing students to work together to create new content (Yang & Moore, 1996; Jonassen, 1996).

The Web appeals to students because it is "compatible with the way students now prefer to learn" (Owston, 1997). The computer is the "children's machine" (Papert, 1993). It is an integral part of their world, they learn and play with it, and thrive on interaction with it. According to Owston, the Web can provide multimedia learning experiences instead of traditional lectures and it can enhance student autonomy and intellectual community. Teachers are not removed from the educational process, but their role shifts from a deliverer of instruction (sage on stage) to a creator of learning experiences (guide on the side). With web-based learning, teaching styles become more project-based than didactic. McCollum (1997) describes a study in which a mathematics professor divided a statistics class into two groups. One group was taught via traditional class lectures, the other studied online. The latter group, which accessed Web pages, electronic mail, and an electronic chat room, performed significantly better on exams.

The Web can open up a vast new array of learning opportunities and better prepare students to contribute effectively in our knowledge-based global economy (Todd, 1996). Natural resources and location are becoming much less important, while there is an increased emphasis on the critical thinking, problem solving, written communication, and collaborative skills that workers possess (Owston, 1997).

Information is instantly available, current, worldwide in scope, and presented in a motivating format. Via the Web, students can explore various types of information, judge their authenticity, compare different viewpoints, analyze and synthesize information, and construct their own knowledge. According to Flake (1996) the World Wide Web can promote socially relevant development and student empowerment.

The Web can supply the opportunity to write to an authentic audience, which is critical in the development of written communication skills. Telecommunications can positively impact students' development of audience awareness (Gallini & Helman, 1995). According to Keiner (1996), "the advent of the WWW as a medium for children's publication opens up a venue for real world publication of a new order". Kneeshaw (1996) describes an activity in which students get actively involved in instigating change by emailing someone who has an impact on the environment.

The Internet can also be used to advance collaboration. Ruberg et al. (1996) found that a computer-mediated communication (CMC) environment promoted experimentation, sharing of early ideas, increased and more distributed participation, and collaborative thinking. An excellent example of a collaborative CMC-based environment is the global discussions among children available via KIDLINK: Global Networking for Youth 10-15.

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Enables New Instructional Models

In A Web-Based Model for University Instruction (Duchastel, 1997), an excellent framework for the development of web-based instruction is presented. Duchastel counsels against "shoeing old models onto the web". Some course designs do not advance beyond using the Web as an information age photocopier when they have the potential to create unique instructional environments by exploiting attributes of this medium. "Access to wide-ranging knowledge on a topic from sources at all corners of the earth creates a diversity of perspectives that ill-fit the typical model of the university course based on a syllabus reflecting the knowledge and perspective of the particular professor offering the course".

Duchastel equates information to power: "those who possess information tend to have an authoritative status in society". Indeed, the Web is a very dynamic medium that is tremendously changing the way that information is distributed and accessed, which in turn affects the distribution of power. Nowadays, anyone can set up a webpage and become a published author. The Web's impact on communication is being compared to the development of the printing press by Gutenberg in the 1400's.

Duchastel's generic model of web-based teaching includes six functions which should replace contrasting elements in the traditional approach to teaching:


1. Specifying goals to pursue instead of content to learn;
2. Accepting a diversity of outcomes instead of demanding common results;
3. Requesting the production rather than the communication of knowledge;
4. Evaluating at the task rather than the knowledge level;
5. Building learning teams instead of working individually or in groups;
6. Promoting global communities instead of remaining localized.

He is very optimistic about universities adopting such a model. Student autonomy and the pursuit of individualized objectives would be promoted while the role of the professor shifts to coaching rather than pouring knowledge into a group of devoted disciples. Post-secondary institutions will have the opportunity to openly compete for students from all over the globe. It is also likely that most will need to enter this competition for survival sakes as well (Anderson & Garrison, 1997; Denning, 1996; Deloughry, 1996). Cooperative (multi-institution) marketing and development initiatives will also be needed (Owston, 1997; Haugen & Ask, 1997).

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Advantages of CMC

Computer-Mediated Communication (CMC) is currently used extensively in distance education, but can also be a useful tool within local learning environments. CMC requires the use of local area networks (for communication within a building) or wide area networks such as the Internet (for longer distance communication). These networks consist of computers which are connected together via any of a number of different media: conventional telephone wiring, fiber-optic cables, coaxial cables, microwave devices, or satellites.

One of CMC's strengths is that it enables both synchronous (real-time) and asynchronous (not at the same time) communication. It also supports communication in several modes of interaction (Paulsen, 1995):

• One-alone: e.g. one person accesses online resources such as online databases or journals, remotely executes software programs stored on a remote computer, or downloads application software via Internet File Transfer Protocol (FTP).

• One-to-one: e.g. two people send messages back and forth via e-mail such as a student corresponding with a teacher or two students communicating.

• One-to-many: e.g. learning materials can be posted to a website by a teacher, forming an electronic lecture which any number of students can view.

• Many-to-many: e.g. any number of participants (students or teachers) interact via a computer conferencing system. Debates, discussion groups, brainstorming, etc. can take place.

The asynchronous communication offered by the web can result in interaction in web-based courses being more thoughtful because students generally take more time to reflect (Kearsley, 1997). Another advantage is that students lose their shyness about participating in class discussions (Paulsen, 1995). Full participation in class discussion by all course members is easier to achieve than in the traditional lecture scenario (Bigelow, 1997). Web-based conferencing can also play an important role in facilitating after-hours faculty-student communication in traditional lecture-based courses (Gillette, 1996). Such conferencing is even more valuable than regular email, especially in large classes. Instead of spending hours replying to individual messages, the instructor can deal with common problems with just one message (Merlic & Walker, 1997).

The Internet also makes synchronous (real-time) communication possible using text, audio or video. Desktop video conferencing (Fetterman, 1996) can provide a new cost-effective dimension of personal contact to web-based instruction, but of course re-introduces time dependencies. Yakimovicz & Murphy (1995) found that interactive video conferencing supplemented with Internet discussion groups provided a collaborative, constructive learning environment.

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CMC as a "Mindtool"

CMC is a "Mindtool" application of computers (Jonassen, 1996) in which the technology facilitates communication between individuals or among a group of people. Jonassen's view is that "CMC affords learners the opportunity to negotiate meaning with individuals ... That negotiation process is supported by a vast array of information that can be retrieved from the network. This process makes CMC the fastest growing and potentially the most powerful of all Mindtools".

The application of Mindtools involves students learning with (rather than from or about) computers. "Mindtools" are computer-based tools and learning environments (e.g. databases, spreadsheets, semantic networks, computer conferencing, hypermedia construction, or microworld environments) which can serve as cognitive tools or extensions of the mind. With the use of such tools, learners can enter an intellectual partnership with the computer, in order to access and interpret information, and organize personal knowledge.

A recent article (Connell, 1997) concludes that "IA" (Intelligence Amplification) is preferred over "AI" (Artificial Intelligence). Educational computing: Learning with tomorrow's technologies (Maddux, Johnson, & Willis, 1997) differentiates between Type I and Type II applications, the latter of which "make available new and better ways of teaching". These authors state that "of all the computer applications that have been adapted to educational purposes, telecomputing holds the greatest potential for revolutionizing the teaching and learning process". Both of these arguments are congruent with the Mindtools approach. There is additional support for the viewpoint that this type of computer use facilitates critical thinking and higher-order learning (Agnew, Kellerman, & Meyer, 1996; Pea, 1985; Vockell, 1989).

The Mindtools approach stresses that technology provides "an array of tools for acquiring information and for thinking and expression [allowing] more children more ways to enter the learning enterprise successfully. These same experiences provide the skills that will enable students to live productive lives in the global, digital, information-based future they all face" (Dwyer, 1994).

Evaluating the Impact of Technology: The Less Simple Answer (Johnson, 1996) presents the view that technology is best used for instructional purposes as an information processing tool: "The use by students at all grade levels of real-world productivity software like word processors, databases, spreadsheets, presentation programs, multimedia authoring tools, e-mail, video production equipment, digital reference materials, electronic indexes, and network search engines to complete complex, authentic projects. Here students will be asked to complete tasks similar to those they will be asked to do in jobs which require using information to solve problems - the kinds of jobs which are both better paying and give greater job satisfaction. The product of such instruction is not a neatly quantifiable score on an objective, nationally normed, quickly scored test. It requires using technology to build personal portfolios of thoughtful, creative work to determine if the use of technology is making our children better citizens, better consumers, better communicators, better thinkers - better people".

Traditional educational paradigms must be shifted somewhat in order to successfully incorporate technology in this way. For technological tools to become student-centered Mindtools requires a readiness for change. For example, school schedules, the physical setup of classes, and assessment of both students and teachers may require modification to accommodate these new tools (Barron & Orwig, 1995).

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Benefits of Hypermedia Construction


Learners can also contribute to the information available on the World Wide Web by constructing HTML documents. Webpage and other hypermedia construction applications are viewed by Jonassen (1996) as superlative Mindtools: "The combination of creativity and complexity required to author hypermedia in a form that is intrinsically motivating to students (multimedia) makes it probably the most compelling and potentially effective of all Mindtools. The richness of representational forms available in multimedia knowledge bases is greater than in all other Mindtools. Future research will very probably documents the effects of designing with multimedia, rather than learning from it".

Multimedia projects can improve educational outcomes by enabling students to represent information using several different media, to link and organize information in many meaningful ways, to draw knowledge and experiences from a wide variety of sources, to practice problem-solving and decision-making, to achieve high self-esteem and to become more self-directed. Such projects include a wide variety of activities and skills which groups can work on effectively over an extended timeframe. They involve a substantial amount of work, open-ended assignments, theme-based activities and interdisciplinary activities. Multimedia projects require and reward good planning and execution skills and students are motivated to create a quality product because a wider audience may view it (Agnew et al., 1996).

A study by Browne & Kinnealy (1997) demonstrated that student home page construction in a computer-assisted language learning (CALL) course was beneficial in terms of second language acquisition and student interaction. The students also experienced a sense of achievement when hearing others' comments regarding the web pages.

Benefits of Internet in Education

• Increasing ubiquity and indispensibility
• Access to interactive and dynamic material
• A million new web pages / day
• 200 million people with e-mail - "infinite" resource
• Easy to "publish" on the web
• Access to people from all over the world
• Can be liberatory and give rise to independent learning
• Can provide a solid platform for group and/or "real world" projects




The Internet Education: Benefits and Challenges

Introduction

Over the past few years, the Internet has emerged as a prominent new technology. The influence of such a powerful technological tool has pervaded all aspects of the educational, business, and economic sectors of our world. Regardless of one's familiarity with the Internet, it is repeatedly made reference to. News broadcasters and commercials, for example, will now provide web addresses, and even the recent movie, "The Net" was sparked by the impact of this new technology (Mike, 1996).

Regardless of whether one uses the Internet or not, one must be clear about the fact that the we have entered a new information age and the Internet is here to stay.

Because the use of the Internet is widespread in numerous fields and domains, without a doubt, it also carries great potential for educational use, specifically second and foreign language education. This paper will therefore focus on the following questions: 1) What is the Internet? 2) How can various facets of the Internet be used in the second and foreign language classroom? 3) What are the benefits of employing the Internet in such a setting? 4) What are the disadvantages or obstacles the Internet presents in a second language classroom? Lastly, the implications of using the Internet in second language classrooms will be discussed.

The Internet is the latest in a series of technological innovations for second language education. In order to understand the role of the Internet, it would be useful to provide a brief history of technology and language teaching, present a survey of the technological resources available to second language learners, and, finally consider the role of the Internet and its possibilities.

Technology and Foreign Language Education: A Brief History

Technology and foreign language education are no stranger to one another. In the sixties and seventies, language laboratories were being installed in numerous educational settings. The traditional language laboratory was comprised of a series of booths, each providing a cassette deck, and accompanying microphone and headphone. Teachers monitored their students' interactions by using a central control panel. The basic premise behind this technology was that if verbal behavior was modeled, and then reinforced, students would quickly learn the language in question. The language lab activities were therefore grounded in a stimulus-response behavior pattern. The more drill practice the students encountered, the faster they would learn the second language. While the language laboratory was a positive step in linking technology and language education, it was soon recognized that such activities were both tedious and boring for learners. Furthermore, the amount of student-teacher interaction was minimal, and individualized instruction was irrelevant. Besides the pedagogical deficiencies, the audio equipment was cumbersome and prone to breakdown, and had only one function-to disseminate auditory input.

These factors put together led to a shift to the communicative approach to second language education, namely, computer assisted language learning.

Microcomputers and quality CALL software provided yet another medium for language learning. Its potential as both a teaching and learning tool are widely written about in the educational literature. At present, there are a variety of computer applications available including vocabulary, grammar, and pronunciation tutors, spell checkers, electronic workbooks, writing and reading programs, as well as various authoring packages to allow instructors to create their own exercises to supplement existing language courses. In addition to the range of software available, CALL has also been shown to increase learner motivation (Blake, 1987).

Chun and Brandl (1992) also propose that the interactive and multimedia capabilities of the computer make it an attractive teaching/learning tool. Computers can provide immediate feedback to students and students can work at an individualized pace. Software can be designed to include sound, graphics, video, and animation. Moreover, information is presented in a non-linear sequence enabling learners to select the exercises or concepts they wish to review.

Despite the advantages and widespread use of CALL, it continues to suffer from criticisms for several reasons. Many believe that learning and practicing grammar rules of a foreign language through fill-in-the-blank exercises, for example, does little to improve a speaker's ability to produce grammatically appropriate utterances (Armstrong & Yetter-Vassot, 1994). Others point out that CALL suffers from its rigidity in light of the complexities of natural languages. For example, a program designed to provide drill practice on French verb conjugation is useful for only that and nothing else. Recently, however, we are beginning to see encouraging and promising results in the area of CALL software development. Interactive video and programs which provide more authentic and communicative task-based activities are being created, which are more in line with the current theoretical and pedagogical views of learning.

What is the Internet?

While the computer is now used in some form or another in most language classrooms, and is considered standard equipment, the Internet is also gradually being introduced in the second language classroom as teachers become more familiar with it. The Internet is a confederation of thousands of computers from various sectors of society such as education, business, government and the military. It is a network of thousands of computer networks (Lewis, 1994). Each individual system brings something different to the whole (databases, library services, graphs, maps, electronic journals, etc), and the end result is a vast accumulation of information. It is a worldwide network of computers that interact on a standardized set of protocols which act independently of particular computer operating systems, allowing for a variety of access methods to the Internet. For example, the Internet can be accessed from an IBM computer in a student's home in Australia, or from a Macintosh computer at a school in Canada. It can therefore be conceived of as the equivalent of a telephone system for computers. It can be used to both exchange information through electronic mail, newsgroups, listservs, professional on-line discussion groups, and so forth, as well as to retrieve information on a variety of topics through the World Wide Web.

The Internet and Electronic Mail

Although the Internet has been available to most people, only recently have educators been realizing the potential the Internet can have in second and foreign language classrooms. The following section will therefore consider some of these potential benefits and advantages of incorporating such technology in language courses. The Internet has been used by some language instructors in creative ways - one of these innovations being use of electronic mail (e-mail), a specific feature of the Internet. Overall, e-mail can encourage students to use computers in realistic, authentic situations in order to develop communicative, and thinking skills. E-mail is easy to use and even teachers intimidated by computers can quickly become adept at using e-mail with their students. Furthermore, even timid or inhibited students can benefit from the meaningful interaction and communication e-mail makes possible. Kroonenberg (1995), for example, employed e-mail in her ESL classes at Hong Kong International School. She relates her initial experiences of working with two classes of ESL multinational students in grades 9-12, and a homogeneous group of summer school students involving Cantonese-speaking 14 and 15 year olds. The Dragon Bulletin Board System (BBS) using the TELIX communications software was established in order to allow students and teachers to send messages to each other, as well as make public entries on discussion conferences.

During the initial stages, students were logged on the system and each student created a password. Students were simply asked to write freely as in a dialogue journal. Kroonenberg (1995) believes this allows students to become familiar with the system and further allows their ideas to flow. Writing on e-mail can therefore be used to generate ideas about a topic, or can enable learners to free-write without any impositions. E-mail can also be used in various conference-type formats or to generate discussion. For example, Kroonenberg often provided students with topics of high interest in order to generate more writing. In fact, one student who was part of this project stated, "I usually get involved in the BBS because the subjects are interesting and I have a lot to say about them" (p. 25). Writing topics often involved school issues or issues that were directly relevant to the students' lives. In other conference assignments, students are the main audience. Students read entries and then respond to them via e-mail. This allows each student to express their opinion. In this manner, all opinions are voiced and heard, something which may not always occur in oral discussions in the classroom.

Chat rooms can also be carried out through e-mail. In this situation, two or more individuals can "talk" on-line about various topics or issues. For instance, language learners can be paired up and can be given a debatable topic to discuss.

Such experiences, once again stimulate authentic communication and assist students in developing specific communication skills such as arguing, persuading, or defending a particular point. Listservs from around the world can offer news and discussion groups in the target language providing another source of authentic input and interaction. Cononelos and Oliva (1993) organized e-mail exchanges between entire classes of students in order to generate discussion, improve writing skills, and promote peer interaction. In this particular project, advanced level Italian students employed e-mail newsgroups to improve both their writing, as well as their knowledge of contemporary Italian society. In this manner, the teaching of culture was also facilitated through the immediate feedback and contact of L2 speakers who were interested in informing others about their culture.

E-mail can also be used to communicate long-distance with language learners in other schools, or other countries for that matter. A study exploring the potential of long-distance communication involving second language learners was carried out by Chang (1993). The goals of the study were to provide students with a real context for improving their writing, help them to expand their ideas of "content-area" reading and functional writing across cultural boundaries, make students familiar with international telecommunications, and investigate with students, the potential effects of telecommunications on literacy acquisition (Davis & Chang, 1994).

The subjects involved in the study included undergraduate students at Taiwan's National Kaohsiung Normal University (NKNU) and students at University of North Carolina at Charlotte (UNCC). The 8-week teleconference began with Prompt 1 in which students were asked to write letters to one another. In addition to personal introductions, students were asked to include a focus on their previous English language learning experiences and the difficulties associated with this. In Prompt 2 and 3, students were asked to use their textbooks on the History of English Language to report on interesting uses of English, (ie. connotations, spelling, etc). Prompts 4 and 5 asked the learners to work with sections of specific texts to comment on pronoun and lexical use, as well as syntactic structure. In the final prompt, both groups of students collected examples of English slang and idioms used in each country's films and music. Questions pertaining to the above were asked and responded to by students in each group.

Davis and Chang (1994) point out that as writers on both sides of the world shared questions and comments, jokes began to surface. Over time, the students' reading and writing began to change as well. Through surveys and informal case studies of student writing during the conference, it was found that for the most part, students' writing had improved in both fluency and organization. Surveys also indicated that students saw some carry over to their study literature, and that they had a better understanding of English usage. While the above examples illustrate a few uses of e-mail in the second and foreign language classroom, without a doubt e-mail can provide authentic communication and can foster awareness of both the language learner and the languages they are learning.

The Internet as a Teaching and Learning Tool

In addition to the communication benefits of the Internet, the Internet can also be used to retrieve and access information. The World Wide Web is therefore a virtual library at one's fingertips; it is a readily available world of information for the language learner. While the Internet offers numerous benefits to the language learner, a few such possibilities are examined here, in the context of language learning.

Perhaps one of the most essential pedagogical principles of language teaching is one that emphasizes the study of language in a cultural context. I, along with many other language instructors believe that language and culture are inextricable and interdependent; Understanding the culture of the target language enhances understanding of the language. To this end, the Internet is a valuable resource to both language teachers and learners. As discussed previously, e-mail on the Internet allows language learners to communicate with native speakers. In this manner, the Internet facilitates the use of the specific language in an authentic setting. The Internet can also be used to acquire information from language resources for a variety of purposes. For example, students can access current information from countries around the world. They can obtain geographical, historical, social/cultural, economic, and political information from the countries in which the target language is spoken. Students can read web versions of daily newspapers and same-day news reports from sources such as the French Embassy's gopher service, the daily Revue de Press (Armstrong and Yetter-Vassot, 1994). Such experiences can allow learners to participate in the culture of the target language, which in turn can enable them to further learn how cultural background influences one's view of the world.

The Internet also serves as a medium for experiencing and presenting creative works. While students can peruse the information on the Net, they can also use it as a platform for their own work such as essays, poetry, or stories. Numerous public schools, for example, are making use of the World Wide Web for publishing student work which can be accessed by other web users. Students therefore become not only consumers of content, but in fact generate the content.

As Mike (1996) describes, the use of the Internet has also been shown to promote higher order thinking skills. A language teacher, for example, may instruct learners to search for specific information. Searching the Web requires logic skills. Once information has been obtained, the results must be reviewed which requires scanning, discarding, and evaluative judgment on part of the learner. The information must be put together to make a complete and coherent whole which entails the synthesis process. Such an endeavor permits students to practice reading skills and strategies. The Internet also promotes literacy for authentic purposes, as stated previously. In addition to being a supplement to reading materials, especially current information, when students are exploring the Net, they are essentially exploring the real world. Such browsing or exploration can also lead to incidental learning as they encounter a variety of information in this way. Communication with native speakers furthers literacy development for authentic purposes, enables language learners to compare student perspectives on an issue, and allows them to practice specific skills such as negotiating, persuading, clarifying meaning, requesting information, and engaging in true-life, authentic discussion. Promotion of literacy also occurs within a social context. The interaction that results from the above situations can lead to cooperative projects and increased communication between students from all over the world, in turn leading to the development of social skills. Finally, use of the Internet can promote computer skills and the technical and conceptual experiences of using a computer.

Lastly, the Internet provides supplemental language activities which can provide students with additional practice in specific areas of language learning. These include reading tests and comprehension questions, grammar exercises, pronunciation exercises possible through the available multimedia capabilities, cloze tests, vocabulary exercises, and so forth. Students can search the Web for such sites, or teachers may recommend specific sites on the Web. Published lists are also available from various sources. For example, Paramskas (1993) offers a list of sites for both language teachers and language learners, some of which relate to issues of language learning, others which use language as a medium for discussion of culture or current affairs, and others which assist in locating native speakers.

The Internet Challenges

Up to this point in time, the above discussion has described some of the potential benefits of the Internet and how it can be used in the second or foreign language classroom. However, such a discussion would be incomplete without addressing the disadvantages or obstacles related to the use of the Internet in the language classroom. While the Internet and its various facets offer a great deal to the language learner, it is not without its problems. The nature of the Internet itself can be a disadvantage at times. When lines are busy due to many users, it may take time to access information or browse the Net and technical glitches themselves can lead to frustration. Lack of training and familiarity on part of the teachers can make it difficult to implement the Internet in the language classroom. This requires that school administrators budget for training in this area. Foreign language teachers are especially anxiety prone to computers since they often have little experience with computers. For the most part, computers in schools are used for business or computer science courses. Costs related to training, as well as on-line costs of using a provider are issues that may interfere with implementing such a technology in schools, especially in schools that have little funding. Censorship may also be a concern to language programs and instructors. The Internet offers access to all types of issues and topics, some of which are unsuitable for children, and this in itself may result in various problems. While some precautions can be taken at the present time, they are not full proof by any means. Equity issues may also present difficulties when attempting to implement such technology in the classroom. As the commercial sector begins to assume a more prominent role in the Internet's infrastructure, rural and inner-city schools, already hard-pressed to provide Internet access, may find it less affordable. This is certainly discouraging for both language teachers and students in such educational settings (Mike, 1996).

Many institutions such as these may also not have the computers or computing facilities necessary to implement such type of technology.

Implications and Conclusion

Despite these limitations and obstacles, it must be realized that the Internet's educational potential is immense. Although electronic, the Internet is an entity related to literacy - people still interact with it entirely through reading and writing. For this reason alone, the Internet is a technology that will, without a doubt, have significant implications for both teaching and learning. So what does this imply for language teachers and learners? Teachers must become familiar with using the Internet and its various functions such as e-mail. They must also learn how to use specific search tools in order to access information, search for lesson plans, or material and ideas to supplement their lessons. Lastly, language teachers must learn now to transfer files from Internet sites to their own computer and vice versa. Obtaining information or literature on the Internet, either through the Net itself, through books, or by attending workshops and courses will further assist this process. To avoid facing the same difficulties or problems associated with use of the Internet, teachers can ask students to keep track of problems that arise during use. In essence, language teachers must take the plunge and approach the Internet as a learning experience themselves. The more enthusiastic and more knowledgeable language teachers are, the more successfully they can implement Internet in the language classroom. For the language learner, the Internet offers a world of information available to students at the touch of a button. While it must be recognized that the Internet cannot replace the language classroom or the interaction between the language teacher and student, if offers a vast amount of information and lends itself to communication possibilities that can greatly enhance the language learning experience.

Certainly at this point in time, several questions need to be asked to guide future research in this area. How can use of the Internet correspond to the communicative or pedagogical goals of language teaching? How will the Internet and its related facets assist language learners in functioning in the global community? What will the real impact of the Internet in foreign language classrooms be? How can the Internet be used more effectively along side the present language curriculum? While these questions have been examined to some degree, researchers and language educators must further investigate and implement this technology to provide others with guidelines in this area.

Without a doubt we are in the center of a "monumental technological paradigm shift, one which will eventually change the way that all instructors teach and the way students learn" (Jensen, 1993). While technology should not take over the language classroom, it must be embraced in order to allow educators to do those things which they are unable to do themselves, or those which will improve what is currently being done in the classroom. As we approach the next century, it is essential that we make informed decisions about how the Internet can be successfully integrated into the language classroom.

posted by Satpal Singh @ 5:57 AM   0 Comments