There is every reason to believe that this trend will continue so that the number of users will grow and grow. In time everybody will have Internet access, making our method even more appropriate and more open then ever. Course participants feel that from day one of connecting to the Internet they can use it for something worthwhile, enhancing their competence within an orderly system.
The increase in the number of home PCs obviously reinforces this trend substantially. Potential students for our courses already have the infrastructure waiting in their homes, which is not the case for everybody participating in distance teaching.
This access service is sold by commercial Internet service providers all over the country. What you purchase is an Internet subscription. What does such a subscription involve?
The students must provide their own:
Students dialling into the net via a modem must complete a logging-in procedure before running their Internet software:
Any private Internet subscriber with his/her own home PC is eligible for NITOL-course participation. We, the providers of the course, must ensure that we only use "standard" Internet software, so that no matter which mail or news application a course student uses he or she will be able to receive our teaching material.
The telephone connection from a PC only allows this one PC to connect to the Internet. A Local Area Network means all computers in a local network are interconnected. This type of connection is most often found at colleges and universities where all local area networked PCs are connected to the Internet.
LAN users log on to their net as usual, and will then promptly have the same access to the Internet and Internet services as to any other service on the LAN. Normally no separate Internet log-on procedure is required.
This means that anyone who is a user in a LAN with Internet access may participate in courses using the NITOL method.
Not only colleges and universities use the Internet these days as the upper secondary school system is rapidly connecting to the Internet by connecting their LANs to the net via ISDN lines.
Thus the infrastructure enabling Internet-based teaching is constantly being developed and expanded.
The question then is: Can all these connections be used in a viable teaching programme, considering transmitting capacities? The answer is yes: this is fully possible the way we have based our system on text, pictures and graphics. It is also true, however, that if you base your teaching on the real-time transmission of video and sound, the quality of the transmitted material may be rather poor if you use a telephone line and modem.
LANs connect to the Internet either via leased lines or via ISDN lines. Leased lines typically have a capacity ranging from 64 Kbps to 1.5 Mbps. An ISDN line has a capacity of 128 Kbps when both channels are in use at the same time. A standard modem today has a capacity of 28.8 Kbps, but quite a few modems doing 9.6 Kbps or 14.4 Kbps are still in use.
For distance teaching applications, the capacity must be large enough to handle the following tasks: 1) distribution of teaching material via news or WWW, 2) discussion in newsgroups, 3) use of e-mail for simple, small text letters and for files as attachments for sending in exercise answers, 4) bulletin boards via WWW.
There is a greater need for transmitting capacity when distributing teaching material and when sending in answers to the exercises. In the other cases, e.g. when exchanging text messages (e-mail and news), capacity is of minor importance.
The greatest need for transmitting capacity most often occurs when sending teaching material. This often entails formatted text with embedded images and illustrations. Such files often occupy several Mbytes, although they can be compressed so they only occupy a few hundred Kbs.
Let us consider some examples:
Modem: A standard modem today has a capacity of 28.8 Kbps. This corresponds to in excess of 150 Kbytes per minute. This is more than enough for our use when distributing lessons and when sending in exercise answers.
Transferring a 2-300 Kbytes lesson will then take two to three minutes. A slower-speed modem obviously needs more time, perhaps five to six minutes for those lessons which occupy a very high number of Kbytes.
Local nets: As stated above, local net capacity in relation to the Internet may vary from 64 Kbps to 1.5 Mbps. Those having the highest capacities will never experience any transfer-capacity problems. Those having capacities of 64 Kbps in their LAN will usually have to share this capacity with other LAN users so that the student may be slowed to approximately the same speed as a modem user.
The World Wide Web is a service which is very useful in the context of distance teaching. It allows downloading of formatted documents with hyperstructures, containing texts, images and graphics. Reports we have had from our students who access the Web via their modems suggest that this works in a satisfactory manner. Usually it is not the modem which is the bottleneck, but some other connection somewhere else in the world.