Embedded questions during a podcast improve knowledge acquisition and retention

If you use podcasts in your instruction, you might want to consider adding interpolated questions (these used to be called adjunct questions) to them. What this means is embedding questions for listeners to consider while listening to the content so as to enhance knowledge retention. Previous research has shown that such questions can improve learning from written materials (see all of the research by Ernst Rothkopf and his colleagues and also the review article of my mentor during my master’s studies Christian Hamaker), from live and recorded lectures, and from video learning material. My first scientific article was on this subject!

In a recent study with medical students, learners who listened to a podcast with such questions performed about 6% better on a knowledge test 2-3 weeks afterwards, compared to their peers who listened to the same podcast without questions. This is similar to research carried out by a successful PhD of mine (Anguelina Popova) with Richard Joiner and myself.


This double-blinded controlled trial randomized trainees from 6 emergency medicine programs to listen to 1 of 2 versions of a podcast, produced de novo on the history of hypertension. The versions were identical except that 1 included 5 interpolated questions to highlight educational points (intervention). There were 2 postpodcast assessments, 1 within 48 hours of listening (immediate posttest) and a second 2 to 3 weeks later (retention test), consisting of the same 15 multiple-choice questions, 5 directly related to the interpolated questions and 10 unrelated. The primary outcome was the difference in intergroup mean assessment scores at each point. A sample size was calculated a priori to identify a significant interarm difference.


One hundred thirty-seven emergency medicine trainees were randomized to listen to a podcast, 69 without interpolated questions (control) and 68 with them (intervention). Although no significant difference was detected at the immediate posttest, trainees randomized to the interpolated arm had a significantly higher mean score on the retention test, with a 5.6% absolute difference (95% confidence interval 0.2% to 10.9%). For the material covered by the interpolated questions, the intervention arm had significantly higher mean scores on both the immediate posttest and retention tests, with absolute differences of 8.7% (95% confidence interval 1.6% to 15.8%) and 10.1% (95% confidence interval 2.8% to 17.4%), respectively. There was no significant intergroup difference for noninterpolated questions.

The article is available here:

Weinstock et al. (2020). Effect of interpolated questions on podcast knowledge acquisition and retention: A double-blind, multicenter, randomized controlled trial. Annals of Emergency Medicine, 76(3), 353-361.


Hamaker, C. (1986). The effects of adjunct questions on prose learning. Review of Educational
Research, 56
, 212-242. Available here:

Kirschner, P. A. (1978). The effect of adjunct question position, type, and the presence or absence of feedback on learning from a videotaped lesson. D. Brook & P. Rice (eds.), Aspects of Educational Technology XII, London: Kogan Page.

Popova, A., Kirschner, P. A., & Joiner, R. (2013). Effects of primer podcasts on stimulating learning from lectures: How do students engage? British Journal of Educational Technology, 45, 330-339. doi:10.1111/bjet.12023

Popova, A., Kirschner, P. A. & Joiner, R. (2014). Enhancing learning from lectures with epistemic primer podcasts activity – a pilot study. International Journal of Learning Technology, 9, 323–337. doi:10.1504/IJLT.2014.067735