This is a series of posts discussing examples of the Curse of Knowledge in instructional design, a phenomenon characterised by the unintended omission of information because the owner of it assumes it is understood.
This example relates to presentations. You undoubtedly have experienced the situation when the presenter opens a page and then immediately scrolls up and down or moves the cursor all over the content whilst discussing something, as in the example below.
The presenter isn’t deliberately trying to confuse you or produce anxiety, but it is what tends to happen as you try to focus and cannot. I’ve written about the manifestation of cognitive overload here. The reason the presenter scrolls through like this is that they already know what the page contains and are familiar with the various sections/components, and so they approach the presenting of it as though it’s simply a familiarisation process for everyone else. Normally however, the viewer hasn’t seen the content before and tries to read or make sense of one bit at a time. The scroll makes this impossible and immediately introduces extraneous cognitive load. The inevitable result is that the whole process is a waste of time, as the viewer can’t make sense of the visual context and most likely isn’t listening to the verbal side as the visual processing usurps the available working memory.
The same thing happens when the viewer instinctively follows the movement of the cursor that darts all over a page.
If you are presenting and want to introduce content that spans more than the single screen, don’t scroll up and down or move your cursor randomly over the content. Apply the multi-media principle of signalling.
I’m Paul Moss. I’m a learning designer at the University of Adelaide. Follow me on Twitter @edmerger