Most of us assume that we learn more from a dynamic or fluent speaker than from one with a lethargic or "disfluent" delivery style, regardless of whether the audience is live, online, or viewing via video. However, a recent study published in Psychonomic Bulletin & Review found that lecture fluency does not significantly affect the amount of information learned. In one of the studies, participants watched two videos in which an instructor explains a technical concept. In the video of the fluent delivery, the instructor stands upright, maintains eye contact, and speaks fluidly without using notes. In the video of the disfluent delivery, the instructor slumps, looks away, and speaks haltingly while using notes.

Perceived learning was significantly higher for the fluent instructor than for the disfluent instructor. The fluent instructor also was rated significantly higher than the disfluent instructor on traditional instructor evaluation areas such as preparedness and effectiveness.

However, when tested on the content of the videos, students remembered about the same amount from each video. Students' perceptions of their own learning and of an instructor's effectiveness appear to be based on lecture fluency and not on actual learning.

This research shouldn't discourage instructors from working to improve their delivery styles, however—especially when delivering video-based training. Delivering a lecture through video, or another digital platform, can make learners feel disconnected before the instructor even begins speaking. Finding ways to combat this disengagement will serve both learners and instructors well.