Videos that lack natural pauses or contain a lot of important visual information can be tricky to describe without interrupting the original audio. In these cases, extended audio description is necessary.

Results revealed detrimental effects of talking heads on the recall of factual knowledge covered in the videos. Interestingly, participants rated their perceived learning as being higher for videos with talking head. Furthermore, participants assigned higher satisfaction scores to videos with talking heads and selected them more frequently when choosing between different formats.

<span>Higher levels of teacher presence have been positively associated with student satisfaction and student&nbsp;</span><em>perceptions</em><span>&nbsp;of learning.</span>

Findings suggest that combining talking heads and annotations in asynchronous video lectures yielded the longest watch time, and highest satisfaction, engagement, and attitude scores.