University of Bergen, Norway

Keywords: Hyperlecture, internet-based teaching, on-line teaching, real media, multi-media, real audio, real time streaming protocol .

Article style and source: Originally presented at Cincinnati Symposium on Computers and History, University of Cincinnati, Cincinnati, OH, May 2-3 1997 and at the XIIth International Conference of the AHC in Glasgow, UK June 30 - July 3 1997

Contents

• Introduction:
• What Is Real Media?
• What Are Hyperlectures?
  • Teaching On Demand
  • Shared Control
  • Additional Resources
• Educational Considerations Regarding Hyperlectures
• How To Put Hyperlectures On The Web?
  • Playing Streamed Media Files Across the Internet
  • The Process From Recording to Broadcasting
  • Syncronising web-pages with audio
• Conclusions

Introduction:

The Internet provides interesting possibilities for teaching, both facilitating communication and the dissemination of knowledge. Quite a few teaching institutions have implemented internet-based teaching tools. The technological development of internet-applications has been extremely rapid, thus providing opportunities in internet-based teaching hardly even considered a few years ago. The hyperlecture, or lecture on demand on the internet, is a new genre of teaching. Real media streaming tools provides the opportunity to transmit high-quality audio as well as video over the internet smoothly. What more, the lecturer can synchronise the web-pages displayed on the monitor with the lectures. Figures, maps, pictures, sources and additional links etc., will appear on the screen as the lecturer proceeds.

This paper will present some thoughts about how the internet can be utilised for such lectures as well as outlining the technical requirements for making hyperlectures available on the internet. content

What Is Real Media?

Originally, audio and video files published on the internet were traditional files such as wav and avi. In order to run these files, it was necessary to download the whole file before executing it. Normally the files were large (1 mb or more) and required a long time for download and lasted only for a short period, like 20-30 seconds. This did not encourage the transfer of media files across the internet, and must first of all be considered as a curiosity when published on the net.

Last year, 1996, several companies involved in hypermedia, agreed upon proposing a standard protocol for serving streamed media on the internet, the Real Time Streaming Protocol - RTSP. This is a protocol similar to the http or ftp, the protocols for transferring web-pages and other files across the internet. The benefit of this protocol is of course the interoperability, like a html-page using the http can be viewed by different browsers (Netscape, Microsoft).

The technology of streaming media allows a more flexible and smooth transferring of media files over the Internet. Instead of downloading complete files, the file is sent continuously as a stream of data. When starting receiving digital information from a media server, the client computer starts uploading this to a buffer. When the buffer is filled, normally after less than five seconds - maybe containing the first minute or so of the file, the media-file can be played. As the file is played, the client computer continues to receive this file into the buffer. The principle of buffers can be compared to a lake. In one end, water run into the lake, and in the other water run out of it. If water is temporarily prevented from running into the lake, the water will still flow out in the other end for quite a while. Unless the flow into the lake (or the buffer) is stopped too long, a stable outflow will be produced despite an unstable inflow. The file is not saved on the client side (though that might be an option), but stream through the computer, like signals in a regular tv-set or a radio. The rtsp-format not only provide an opportunity to stream a file, but also compress the file first before publishing. The extent of compression depends of course on which sound quality that is chosen.

Normally, two different servers are used on the server side. First you need a web-server for your traditional web-pages including text and graphics. The other server, the media server, can be located anywhere as long as it has a network connection with the web-server. From an html-page on the web-server, a media-file on the media-server is called. The task of the media-server is to feed the client computer with this file, a stream of digital information that is decoded to sound and/or video in the client computer. The client computer has of course no need of server-programmes, but need a media player installed for decoding the streamed media file. However, a separate media server is not required, as the streamed audio files can be located at a web-server. The method is beneficial because it simplifies, the disadvantage is that it is less robust than using a media server.

Furthermore, a streamed media file may be synchronised with web-pages. This provides the possibilities for multimedia presentations on the net, or as I've called them; hyperlectures. I will return to a discussion of the technical requirements at a later stage. content

What Are Hyperlectures?

There are different genres within teaching, genres who all require different pedagogical tools and approaches. This also means that the different genres expose students to different learning situations and subsequently methods of perception through different incentives and challenges. Lectures, group teaching, text-books are examples of different genres of teaching.

The most significant difference between the genres is the extent of interaction and control between the teacher and student. A lecture is traditionally a person speaking over a given topic, maybe with the use of tools like blackboard and overheads. The lecture is a forum where the lecturer can put forward his or hers arguments in a structured and linear form. Interaction between teacher and student may occur, but the teacher is controlling the contents and progress of the lecture. In group, or seminar teaching, the teacher is only one of several participants with the task of organising a debate. The control of the contents and direction of the discussion is limited compared to a lecture. On the other side, a text book gives the teacher complete control ruling out interaction all together.

The hyperlecture is a new genre of teaching and contents and pedagogical advantages and drawbacks to the genre need to be deployed. Briefly, a hyperlecture is a multimedia lecture transferred on the internet. Normally this would mean an audio file containing a lecture with possibilities to synchronise this visually. The audio content can be accompanied with text, figures, maps, sources, pictures, video or whatever a web-page normally may contain. The synchronised web-pages automatically changes on the client screen after a timetable set by the author. This means it is possible for the lecturer to comment upon the resources dispalyed on the client screen. Naturally, a web-page may contain links to other pages not directly related to the lecture. The hyperlecture can be stopped, halted, rewinded or forwarded by the student at any time. The genre can only be evolved through experiments and thereby experience gained. Still, it should be possible to indicate some concepts of the genre and the pedagogical difficulties and possibilities involved.

First of all, it is very important to emphasise that this is a new genre of teaching. It should not be done simply by recording some old lectures, putting them on the web accompanied with some illustrations, maps etc., that might seem appropriate. The hyperlecturer must have a conscious attitude towards the features the hyperlectures present; the integration of different media. This must always be kept in mind. Otherwise the combined use of different media will only end up confusing the student. A hyperlecture should not contain an independent lecture that could be hold in a traditional lecture hall or printed, and independent sets of maps, figures, sources and exercises. All the information must be integrated in one teaching package. Now some of the obvious features of hyperlectures. content

Teaching On Demand

An essential feature of the hyperlecture is the availability on the internet at any time. This means that attending the lecture is independent from time or place. The lecture comes to the student when and where the student wishes, instead of the student coming to a lecture hall at a certain time. Hyperlectures are thus teaching on demand. Distant students are not only separated from the lecture hall physically, but are also often full time employed and have family obligations. This leave time for studies limited and require flexible solutions for studies. Thus, hyperlectures facilitate distant teaching, not only by letting the student live far away from the university, but by letting the student order the lecture at wish. The flexibility is one of the greatest benefits to the hyperlecture.

Not only distant students may appreciate this. Regular students who normally attend the lectures may have the same need of flexible solutions. Besides, if a number of lectures have been made available, students may `order' a lecture on a certain topic, useful before exams to fill knowledge gaps.

An exciting possibility hyperlectures offer is exchanging teachers between universities. Different history department may specialise in different fields and periods, and hyperlectures may make lectures by the most prominent historians available to any student at any university or college.

At this point though, it is necessary to point out that hyperlectures are not to replace traditional lectures, but complement them. The hyperlecture cannot replace the direct contact between lecturer and student and the possibility for an immediate interaction between lecturer and students. Furthermore, a hyperlecturer lacks the opportunities to grasp the students' perception of the information presented to them, and the opportunity to adjust the presentation as the lectures proceed. The technophobic and techofanatic approach is equally important to avoid. content

Shared Control

The teacher and the student share control over the hyperlecture. The teacher decides what to be available and the path to follow, but the student has also considerable control. To have a lecture started whenever wished, is part of this control. Furthermore, the control panel available allows the student to stop, pause, re- or forwind a lecture at any time. One may wish to have parts of the lecture repeated, and this can be done by rewinding the lecture at wish. Also, a lecture may be paused for a while to give the student time for contemplation. Furthermore, the hyperlinks available on the accompanying web-pages, may be followed. The link may be a new lecture elaborating on a topic or simply more information such as maps, pictures, historical sources or literature. As long as the lecture proceeds, the lecturer has control in the sense that he/she decides what to talk about, and the synchronising features `drags' the student back on track. content

Additional Resources

Like the shared control, the hyperlinks facilities make the hyperlectures differ from regular lectures. As I will return to, the amount of information synchronised with the lecture, should be limited, but the pages may contain a wide number of relevant links. When the lecturer is talking about the Declaration of the Rights of Man and of the Citizen from the French Revolution in 1789, it may be interesting for the student to have that particular source put up on the screen or at least just a mouseclick away. Likewise with maps, charts and figures, or even abstracts of historical literature. Thus the students may widen their knowledge and have the opportunity to elaborate on parts of the lecture. And, which is also very important, the student may more easily be critical to the arguments of the lecturer or contradicting historical opinions presented when having more material, especially background material like sources, available. The interpretation of sources may not always be that obvious, and by providing the source as an additional feature to the lecture, the teacher encourages the students to a more independent and critical attitude towards prevailing opinions.

The additional resources may also contain interactive applications. A set of exercises may be developed to the complete lecture, or to more elaborated sections, taking advantage of the extra material provided. The lecture as such, and maybe especially the exercises, may promote a debate between students and/or between students and lecturer. Electronic seminars connected to the hyperlectures' web-page will make such a debate possible.

Furthermore, the web facilitates distribution of more untraditional material. Both historical video and audio sources can be made available to the users, thus giving the students opportunity to study such sources on there own. Access to such material is otherwise normally limited to students specialising in this field of history. By doing this, the students will get a wider perspective of history and emphasise that historical sources are not only written sources.

I would say the most important pedagogical feature of the hyperlecture is the opportunity to impel the students to an active utilisation of the lecture and the adherent material. Learning through active participation and exertion is far more efficient than learning through passive reception of information. content

Educational Considerations Regarding Hyperlectures

Hyperlectures have not yet been implemented at any universities that I know of. This means we have little experience in what effect such lectures have on the students and what educational considerations should be made It is important to keep in mind that hyperlectures are something totally new in teaching and not commit the mistake of believing that it is just a regular lecture put on the web and have some figures to go with it. Despite the lack of experience, some educational thoughts can be outlined.

The major challenge is to keep the student's concentration. This is a challenge for several reasons. Naturally, it is impossible to control how the perception of the lecture is and thereby adjust the lecture as it proceeds. Moreover, it is important not to expose the student to information overload. An overwhelming amount of visual and audio resources only end up making the student confused. This is really the same problem many experience in a traditional lecture - combined use of blackboard and/or overheads may compete over the concentration. Either the student listen to what you say or is busy writing off the blackboard. Again, this underlines how important it is to integrate the information presented, the student exploration of the material must be done within the bounds of the lecturer's conscious selected path. The synchronised information in a hyperlecture should be limited and it's main function to emphasise the most important points in the lecture. No new information, like a complex figure or more extensive textual abstracts, must be presented, at least not without being highly integrated with the audio information. Such additional material must be made available through links to other pages.

The opportunities to hyperleaps during the lecture is another educational consideration to bear in mind. It is only normal that the students may be utterly attempted to pursue the links to exciting and interesting resources. This is of course hard to prevent, and maybe the best solution to it is to limit the length of hyperlectures to maximum 10 to 15 minutes, compared to the more traditional 45 minutes in the lecture hall. Instead of few but long lectures, the hyperlectures probably should be short and maybe more numerous. The toil the students have to put into a ten minutes hyperlecture with extra material made available, might be as much as at a regular lecture. Probably the efforts are more considerable since the students will be encouraged to a more active utilisation of the material. Also the shared control of the lecture allows the student to be more active than during a traditional lecture. The most efficient way of using a hyperlecture would probably be to "attend" the lecture as a passive student first, after getting this first grasp of the topic and contents of the lecture, and then restart the lecture using the controlpanel more actively and also to pursue the links to additional resources. Hopefully, the student will also have some thoughts and questions to bring into the additional material. content

How to Put Hyperlectures On The Web?

Making hyperlectures available on the net is quite simple, not requiring expensive equipment or complex software. All you need is standard software and hardware accompanying any multimedia computer, two kinds of servers; web- and media servers and software to stream media. As mentioned, though a media server is recommended, it is not required as the streamed files can be uploaded to a web-server.

First of all you need an audio file. This can be recorded directly with a microphone connected to the computer or by connecting an external device like a recorder. In any case you'll need software producing wav-files, software that may easily be acquired on the net if not shipped with the computer.

There are different media servers available for download on the internet, the two most common are Netscape's Media Server and RealNetworks' RealVideo/Audio servers. The most commonly used is the software from Progressive Network (http://www.real.com). Their software is very easy to use and can be recommended for first time users. Anyone will have the first short "hyperlecture" up running after a few hours work. Different software is needed for:

• Software to record audio
  
• Playing streamed media-files across the Internet
  
• Converting wav-files to rtsp format.
  
• Server to transmit rtsp format files
  
• Web-server software

Playing Streamed Media Files Across the Internet

In order to listen to streamed audio or video files across the Internet, a media player is necessary. When a media player is installed, it will automatically be launched when a media-file is called using a web-browser. Figure 1 is a screen copy of the Progressive Network's media player. The player allows you to start, stop, halt, re- or forwind the audio-file and to adjust the volume. In addition it gives information about the file, such as title, author, copyrights, length, sound quality etc. The player is not needed for transmitting audio, but is needed for receiving such files. This is the only software the client side needs in addition to a web-browser. content

The Process From Recording to Broadcasting

The process in short is: First, record the hyperlecture as a wav-file. In some of the audio editors you may save the file directly as a streamed media file (Real Audio - ra-file). But Real Audio ha an encoder of their own that can be used for this purpose. An input wav-file is selected with an output ra-file as the result. When a media server is used, this ra-file must be stored on the media server. Otherwise, the file can be stored at the web-server. As soon as this is done, the ra-files can be called and played by the media player by typing the url to the media file. Figure 2 illustrates how the real audio file jantest.ra is called from the media server web.hist.uib.no. (Here, pnm is equal to http for web-pages). Having made the audio-file available on the Internet, the next step is to call a media file from a web-browser. This is done in a two-step process. In the web-page, there needs to be a link to a meta file (with rpm-extension), say jantest.rpm. The rpm-file is a simple text-file containing the url to the Real Audio file (see figure 3). content Figure 3: Files on the web-server

Before this will work, the web-server needs to be configures to recognise the rpm-files, and to send back the correct information in order for the browser to launch the media player. This is done in the web-server's MIME type, and the exact proceedings is described on the RealNetworks home pages. content

Syncronising web-pages with audio

A benefit of using the Internet to transmit a lecture is the possibility to syncronise the audio with visual information. I will not describe this process in detail, just say that it is a simple two-step process as well. First a text-file with the syncronising infomration must be made. This file hold the information when an event is to start, that is when a certain web-page is going to be displayed, when the event should be stopped and what url to display, as shown in figure 4. The next step is to merge this file with the Real Audio file by using a tool RealNetworks provide. This ra-file must be stored either on the media server or on a web server.

The technical bit may seem difficult and discourage the development of hyperlectures. However, we are already seeing the same development for these tools as we have seen for word processing and web-publishing. Tools and wizards are made that make no technical skills really necessary, making the whole process extremely user friendly.

Figure 4: Example of a text-file containing syncronising information:

u 00:00:03.0 00:00:05.0 http://web.hist.uib.no/internettlyd/test.htm
u 00:00:05.1 00:00:09.0 http://web.hist.uib.no/internettlyd/test2.htm

Conclusions

The lack of experience in using media streaming tools should be an incentive to put some efforts into this. The technology has no doubt a great potentiality, and the ease of use of software should not disencourage anyone from experiencing in the field. A first step is naturally to get acquainted with the software and technical requirements of doing this, the next one, and a very important one, is to deploy the educational aspects of such teaching. I have focused on this last aspect, partly because the technology is tolerably simple, but first of all because the main idea behind hyperlectures is to take advantage of a new genre of teaching, making the educational considerations very important. content

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