Immediacy and Bandwidth
Some students’ access to technology may be uncertain, therefore low bandwidth - low immediacy tools (green tools in the diagram below) are your best bet. Use higher immediacy and higher bandwidth tools when you have a clear learning purpose for doing so, but have a back-up plan.
Immediacy means how quickly the participants in an interaction can respond to one another. A conversation between two people sitting at a table is extremely immediate; a conversation taking place via an online chat tool is nearly as immediate. Email is less immediate – someone might take hours or days to respond; likewise with online discussion groups. Prerecorded video is very low immediacy: there is no interaction between the instructor and the student unless it takes place by email or in a discussion group after the student has watched it.
Bandwidth refers to the rate of data transfer, similar to how much water can travel through a hose. Tools that require low bandwidth are ones that are text-based like email, chat, discussion groups, and so on. Tools requiring medium bandwidth are those that are audio-based like podcasts and mini-lectures or discussions that make use of audio but not video. Tools that require the highest bandwidth are ones that employ video. Moreover, live video requires a more “robust” bandwidth than recorded video, which makes it more prone to “freezing” and dropping out than recorded video.
Both immediacy and bandwidth should be considered when choosing an online tool. Using limited or compromised bandwidth – for example, a data plan on a smart phone – students will be challenged to participate in a live video presentation. A recorded version might be preferable. If an online meeting with a student doesn’t require video, use just audio. If the student needs to see something the instructor is doing during the meeting, and needs to be able to ask questions while it is taking place, then live video may be the best option.
The chart below will help you think through the dimensions of immediacy and bandwidth (a larger version is also available as a PDF).
Tools in the green (lower left) quadrant are the “unappreciated workhorses” – they’re not fancy, but get the job done. The blue (lower right) quadrant represents tools that provide practical immediacy; the yellow quadrant (top left) includes tools that provide audio and video on demand (yellow); and the red quadrant (top right) represents tools that emulate face-to-face conversations, albeit with high bandwidth demands.
The blog post Videoconferencing Alternatives: How Low-Bandwidth Teaching Will Save Us All offers more insight on teaching with low-bandwidth tools.
Waterloo’s Centre for Extended Learning explains the principles and process by which they develop their online courses in How People Learn, Abridged Version.