Computer World. Матросова Т.А. - 85 стр.

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Hy bri d. The slow speed of modem connections has led to the use of hybrid
connections. In a hybrid Web-based classroom, a CD-ROM is used to distribute
large amounts of information, and a modem connection is used to provide
updates and communication. Hybrid connections are a compromise designed to
address the problems of current technology, yet they increase development cost
due to the need to merge two different environments. As home connection
speeds increase, use of hybrid connections will dec rease.
None . From one perspective, this connection category is the hybrid
approach without the network connection. It is important because, regardless of
the hype surrounding the technology, a large proportion of people in the world
still cannot gain access to the Internet. Some of these people have access to
computers and therefore can still use many of the elements of a Web-based
classroom (documents and self tests, for example). However, they will not
benefit from the immediate communication and sharing of information possible
with one of the other three connection categories.
From the point of view of users, a connection is judged on two essential
characteristics: speed and cost. The faster a connection, the less time it takes to
retrieve information from servers and the less time the participant has to wait.
Generally, the faster the connection, the more expensive it is in purely monetary
terms. On the other hand, a slower connection, although financially less expensive,
will cost more in time lost waiting for information to download and possibly result in
frustration. Another important characteristic is how the cost of the connection is
calculated. Construction of a LAN has a large up-front cost, some ongoing
maintenance charges, and usually no usage charges; generally the cost is paid by the
institution. On the other hand, a modem connection from home might cost less than a
few hundred dollars, but it is usually paid for by the student.
Protocols. Client and server software use network connections to communicate
and share information. However, before they can do so they must agree upon a set of
rules that govern how they can communicate; such a set of rules is called a
communications protocol. The Internet uses protocols that belong to the TCP/IP
protocol stack. The stack is a collection of protocols that each belong to one of four
layers. The top layer defines the application protocols that software such as Web
browsers and e-mail programs use to communicate with appropriate servers.
How Can You Use It?
What can be done with a Web-based classroom is limited only by the
imagination of the educator and the available resources. Because a Web-based
classroom is an extension of the educator who built it and designed with a particular
situation in mind, the range of possibilities is almost endless. This variety means that
we can't describe all the possibilities of a Web-based classroom within this article.
Furthermore, only now are people starting to fully understand how to use a Web-
based classroom without treating it like a horseless carriage–simply doing

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