Do Explainer Videos Help Students Learn?

Does adding video to teaching improve learning?

Yes. Across 105 randomized trials with 7,776 students, adding video to existing teaching produced strong learning gains (g = 0.80), while replacing teaching with video produced small gains (g = 0.28) (Noetel et al., 2021).

The lesson for teachers: use explainer videos alongside your teaching, for pre-reading, revision or students who missed a class, not as a substitute for it.

Why do pictures plus narration work better than text?

In 13 experiments, learners given words plus graphics outperformed learners given words alone on transfer tests, with a median effect size of d = 1.35 (Mayer, 2023). Spoken narration beat the same words printed on screen in 18 of 19 experiments (d = 1.00).

So the most effective explainer shows a picture of the idea and says the words, rather than putting paragraphs on screen. That is the format DistilBook generates: an illustration for each idea, narrated.

Does the tone of the narration matter?

Yes. A conversational narration style beat a formal one in 13 of 15 experiments (d = 1.00) (Mayer, 2023).

Mayer's review also found a human voice beat a machine voice in 6 of 7 comparisons, while noting that modern text-to-speech is closing that gap. If you use an AI voice, write the script conversationally and review it before generating, which is exactly what DistilBook's narration step is for.

How many teachers already use video in class?

Most. In a 2026 survey of 393 US pre-K to 12 teachers, 76.5% used YouTube to teach, about half of them daily or weekly, and videos took up 17.9% of teaching time (Pritchard, Carpenter and Rosenberg, 2026).

Students are already there too: 90% of US teens use YouTube and 73% use it daily (Pew Research Center, 2024).

Can AI save teachers time on making materials?

Teachers who use AI weekly report saving about 5.9 hours a week, roughly six weeks over a school year, and preparing to teach is the most common use (37%) (Gallup and the Walton Family Foundation, 2025).

Turning an existing lesson PDF into a narrated explainer is one of the clearest cases: the material is already written, and the video is generated from it.

Sources

Every number on this page comes from the sources below.

• •Noetel, M., et al. (2021). Video improves learning in higher education: a systematic review. Review of Educational Research 91(2).
• •Mayer, R. E. (2023). Research-based principles for designing multimedia instruction. Society for the Teaching of Psychology.
• •Pritchard, Carpenter and Rosenberg (2026). Educational Researcher. doi.org/10.3102/0013189X261457604
• •Pew Research Center (2024). Teens, Social Media and Technology 2024.
• •Gallup and Walton Family Foundation (2025). Teachers and AI survey, 2,232 US teachers.