Phenomenal success of WWW could not but cause groundless excessive expectations in respect of all "Internet-like" technologies. A vivid example of this kind is, in our opinion, the concept of a hypertext manual.
A hypertext manual is an electronic version of a common manual, in which the educational text is added with navigation facilities, hyper-references. Hyper-references present a simple but powerful tool. But they are ABSOLUTELY unfit for navigation in the MANUAL text. Any student "by definition" possesses a connected presentation of the compulsory knowledge minimum on a particular subject. It is intended for CONSISTENT serious studying, and not for "surfing". Of curse, quick navigation is necessary in the process of information retrieval (selection of materials for a thesis, report, etc.) But information retrieval is another task. You should search for information in encyclopedias and Internet. In studying the MANUAL hyper-references are rather harmful than useful, since they distract the student from the studied topic switching his attention to information weakly related to the paragraph subject. Freedom of navigation results in the following: after a number of switches the user forgets where he came from and what the purpose of his studies was. Eventually he becomes just confused instead of obtaining a consistent system of knowledge. Most beginner WWW users are well aware of this "hypertext mind" condition.
Recently developers of hypertext manual have started to call them hypermedia manuals referring to the presence of various illustrations in the editions, including audio and video information. Presence of illustrations is good. The trouble is that they are rather few in hypertext manuals. Moreover, even working with a richly illustrated hypertext manual (as well as in case of WWW) the student first of all reads the text, because it is the text that contains the main information, the text makes the "core". Reading text from the screen is one of the most harmful forms of computer work for the students' eyes. Fatigue is much higher when in case of reading a conventional book. Ophtalmologists testify that during recent years the number of schoolchildren suffering from eye diseases has jumped drastically, and unwise use of computers has contributed to the process.
We believe it principally important that the major educational material should be presented not in the form of hypertext with occasional illustrations, but as vivid well-directed multimedia lectures. Coordination of the lecturer's voice, musical and noise accompaniment with visual information may guarantee imaginative comprehension of the educational material, affect the student's emotions, thus not only giving more profound and "durable" knowledge, but also relieving the burden on the students' eye.
To make the process of subject-oriented studies at schools computer-aided we need solid arguments. Hypertext manuals do not provide any. It is difficult to implement an effective teaching method basing on a hypertext structure, as well as a teaching scenario (studies of educational material -> control over comprehension of the studied material -> finding of poorly learned material and motivation to its repetition -> awards for successes).
We do not know any hypertext manual, which has received any wide recognition from the users and experts as an efficient methodical tool. On the contrary, multimedia programs, whose core is not the text but the sound and screen tasks replacing one another in turn according to the educational scenario, have a good reputation among the users and experts. For example, as a result of polls among teachers and specialists in educational methods participating in the seminar Computer-aided methods of educational support of the subject of History in the secondary school, the first two places were won by editions consisting mainly of sounded multimedia staged lectures (see http://www.history.ru/anketa.htm).