The transmitter at Alexandra Palace, London, for the OU's TV and radio programs

In an earlier post, I listed the seven ‘aha’ moments that have been the most seminal ‘discoveries’ in my researching and working in educational technology. This is the third of seven posts that discuss why I believe these ‘discoveries’ to be important, and their implications specifically for online learning. The others to date are:

1.  Media are different.

2. God helps those who help themselves (about educational technology in developing countries).

What was the discovery? (1978)

Everyone learns better from media and technologies that allow them to study anywhere, at any time. In particular the ability to repeat and revise recorded material makes learning much more effective than live, synchronous teaching, for any learner who requires flexibility in accessing educational opportunities.

Which are synchronous and which are asynchronous technologies?

From Bates, A. (in press) Technology, e-Learning and the Knowledge Society, London: Routledge

From the table above, it can be seen that synchronous technologies include both one-way (broadcast) technologies, such as lectures, radio, broadcast television, and Webcasts, and two-way (interactive) technologies such as face-to-face seminars, audio-conferencing, video-conferencing, web conferencing, and virtual worlds. The unifying feature of synchronous technologies is that they take place in real time; thus both teachers and students have to be communicating together at the same time (but not necessarily in the same place.)

Asynchronous technologies include both one-way (broadcast) technologies such as print, audio-cassettes, podcasts, video-cassettes, lecture capture, web sites, DVDs, databases, web streaming including YouTube videos, and xMOOCs, and two-way (interactive) technologies such as written assignments, e-mail, online discussion forums, learning management systems, e-portfolios, blogs, search engines,cMOOCs, and other social media such as Facebook. Synchronous ‘content’ can be made available ‘asynchronously’ through recording.

How did this discovery come about?

To be honest, this insight really came from work by my colleagues at the Open University, Hans Grundin, Duncan Brown, Nicola Durbridge and Stephen Brown. As part of the Audio-Visual Media Research Group, we were tracking student participation in the television and radio broadcasts that accompanied the Open University courses. The latest technology in the early 1970s was the battery-operated radio cassette player (the Sony Walkman did not arrive until 1979). This allowed students to set a timer which would automatically record a radio program on to an audio cassette. The research indicated that increasingly students were recording the radio programs to listen to them later, but more importantly they were rating the cassettes as significantly more useful to their studies than the radio transmission.

There were many reasons for this:

  1. The OU radio programs were often transmitted at difficult times, such as 6.00 am or midnight.
  2. Students could stop, rewind and replay the cassettes.
  3. We found that students were working on the print materials on average roughly a week to ten days behind the recommended schedule. Thus the recorded version was more in synch with their actual study pattern than the broadcast.

As a result the university started up an audio-cassette library service, whereby students could order a cassette if they missed a program and have it mailed to them. Also the university started designing audio-cassettes that were not broadcast but accompanied the printed material that was the core of the studies. Instructors began taking advantage of the ‘affordances’ of the cassette technology, in several ways:

  1. Integrating the cassette very tightly with the printed material. For instance, John Mason, a mathematics instructor, used the audio cassette to talk students through equations and mathematical formulae in the printed text, very similar to the way Salman Khan talks student through a video version in the Khan Academy – but 40 years earlier
  2. Making use of the stop-start cassette facility to build in exercises and activities for students to do, with the feedback/answers later on the cassette tape. (Because you have to search ‘blind’ through an audio-cassette, it prevents students jumping straight to the answer.) For a full list of the ‘affordances’ of audio that were identified through the research of the AVMRG, see: Pedagogical roles for audio in online learning

In the end, the audio cassettes became so popular that by 1980 the BBC/OU almost entirely stopped broadcasting radio programs directly linked to course units .

When the video-cassette recorder arrived in the late 1970s, we found exactly the same pattern. The cassettes were rated more highly than the television broadcasts, and at one time the university was operating a system whereby more than 200,000 audio and video cassettes a year were being shipped out to students.

Why is this significant?

Because it suggests that asynchronous online learning is almost always better for learners requiring flexible learning than classroom teaching or ‘live’ broadcasts. In particular, despite the different ‘affordances’ of different media, there are some common advantages across all asynchronous technologies. In particular, students have greater control over asynchronous technologies, enabling them to fit their learning more easily into the rest of their lives, and also to repeat, and practice, until they can achieve mastery.

However,  there are circumstances where there are advantages in synchronous teaching. One obvious example is teaching oral language skills. Real-time communication in a foreign language is an important competency, so while recordings can help, students will need to practice in real time. There are circumstances where a live lecture or classroom can be more effective, for instance when trying to build a sense of community with a class, to provide an overview or summary of a whole course, or to provide inspiration or motivation to students.

Furthermore, as with all media, there are other variables which may have a large influence on effectiveness. For instance, a well-managed face-to-face seminar is likely to result in greater learning than a poorly managed online discussion forum; quality matters. Students looking for a campus-experience and direct social contact with other students are more likely to benefit from synchronous communication opportunities such as lectures and seminars.

But I woud argue that over a very broad range of circumstances, learners will on balance benefit more from asynchronous technologies, because of the extent to which they can control the pace and place of learning, and this is of particular significance for distance and/or lifelong learners.


This is probably one of the most controversial of my aha moments. There are many instructors for instance who believe very strongly in the advantages of real-time teaching, such as a lecture or seminar. Others swear by webinars (which can of course also be recorded).

Thus your comments on this will be particularly appreciated, particularly if you have research evidence to support your views.


There are 300 research reports from the AVMRG at the Open University. They are now difficult to access, but the Open University library has a complete set of papers, from 1 to 300, preserved within the University Archive. They are catalogued in the main Library catalogue where they can be found by searching for a related topic or by searching for “AVMRG”. Visitors to the Library are welcome to access the reports within the University Archive.

Much of the research is summarized in the following books:

Bates, A. (1986) Broadcasting in Education: An Evaluation London: Constables

Bates, A. (2005) Open learning, e-Learning and Distance Education London/New York: Routledge.



  1. This is a really interesting post. I was discussing this with a co-worker last week. We were both agreeing that we find the out of class, asynchronous learning to be more effective.

    1. Students can chime at a convenient and comfortable time for them.
    2. Students can go back and reflect on what they posted.
    3. Students can read what others have posted and refine their own thinking.
    4. The teacher can participate both with specific students and the whole group.


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