Sunday, April 12, 2015

Time-shifted Learning: Merging Synchronous and Asynchronous Techniques for E-Learning

A team of ANU computing students is working on my "Better Webinar Tool For Teaching" concept. The aim is to produce a free open source webinar plug-in for Moodle. The key feature of this is to be that the student can pause a live video/audio session, just as they can time-shift a live-to-air TV broadcast, using a Personal Video Recorder (PVR), such as a TiVo. The idea would be that if you, as a student, are interrupted while taking part in a webinar, you can press "pause", go away for a few minutes (or days), then come back and resume your participation.

On the face of it, adding a pause to webinar software does not sound like much of an advance over products, such as Adobe Connect and Blackboard Collaborate. Those products already provide the option of viewing a recording after the webinar is over. However,  the subtle point is that a pause function in a live webinar blurs the distinction between synchronous and asynchronous e-learning. The function may be technically not too hard to implement, but what does it do to the pedagogy?

Webinar products allow students to do more than just watch a video conference. The student can actively participate by typing in text, responding to multiple choice questions, by speaking and being seen. However, these interactive functions are only available during the live webinar, students cannot interact using the recording after the webinar is over. Such interaction makes no sense in terms of a fixed recoding of a completed synchronous learning event.

Participation after a delay is normal for asynchronous e-learning. Products, such as Moodle, provide functions for students to interact minutes, hours or days apart. Why can't these same functions be used for a synchronous mode? If you missed the live webinar, why can't you still answer the quiz and type in some comments?

There may be some limits place on how long after you can participate in an event, for reasons of practicality and pedagogy. Time limits on student participation are are normal in education [a concept I explored at length in the paper Worthington, (2013)]. But there is no technical reason why the student has to use different software for synchronous and asynchronous modes, or why there needs to be any firm division between the two.

Explicitly allowing for delays may also ease some of the technical constraints on webinar software. Video and audio conference systems normally try to present content in "real time", requiring buffering of the data and delays beyond those inherent in the telecommunications system. An asynchronous system could present information as soon as it is available, even if it is out of sequence. Research shows that people tolerate such mis-ordering if it happens only over a few seconds (and those watching a later recording could have it resequenced).

What seemed to me a relatively simple concept is something I have spent several years trying to explain, to colleagues and to students. My latest attempt is with the PVR metaphor, using the term "Time-shifted Learning". A paper on this is in preparation for later in 2015.

Before settling on "time-shifted" other terms I considered were "pausable" (too clumsy) hybrid (already used as a synonym for blended), time in various ancient languages (already used as product names) and Synchromodal (already used for the combination of live classroom and synchronous learning).

ps: A simple pause function on webinars could also be used as a replacement for lecture recording software, such as Echo 360. A recorded lecture could be thought of as a webinar with no one watching live. Such a function would still be superior to a simple recording, as it would still allow the class to interact later.


Worthington, T. (2013). Synchronizing Asynchronous Learning: Combining Synchronous and Asynchronous Techniques. In Proceedings of 2013 8th International Conference on Computer Science & Education (ICCSE), 26 Apr - 28 Apr 2013 , Sri Lanka. URL:

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