Case Study 1 — Does Adding Video Actually Help?
A controlled study of short supplementary instructional videos in an asynchronous online graduate course.
The problem
Every instructional designer I know has been asked the same question by a client — should we add video? It is an expensive question to answer badly, because video costs money to produce, time to produce well, and once it exists somebody has to caption it, host it, keep it current, and eventually replace it. I had opinions about the answer, and no evidence, and neither did most of the people around me.
So, I created an independent study and narrowed the question until it was small enough to test. In an asynchronous online graduate course with no instructor present, does adding short instructional videos change student engagement, satisfaction, or performance?
The decision
I built two versions of the same four-module networking course. The control version was text-only, and the treatment version was identical in every respect except that each module carried a short video summarizing its content.
The specification is what made this a study rather than an anecdote. I did not produce the videos to my own taste. I derived a specification from the research first, then held every video to it — three to six minutes, one video per module, one main idea per slide, narration that summarizes the module rather than reading the text aloud, visual signaling on the key ideas, one or two embedded reflection questions, captions enabled, and an identical structure across all four.
Generative AI carried part of the workflow under a published declaration, deriving the design checklist from five research articles, drafting the slide outlines and narration against it, preparing an IRB-ready consent form, generating assessment items, and running the preliminary analysis.
The proof
Participants consented, were assigned to a group, completed the course and its assessments, and completed two surveys. Behavioral engagement came from quiz scores, completion time, and final examination scores, and attitudinal data from adapted Online Student Engagement and eLearning Student Satisfaction instruments, both reliable at Cronbach’s alpha of 0.85 and 0.81. I ran Welch’s t-tests with Cohen’s d, plus a thematic analysis of field notes and interviews.
The video group reported higher satisfaction, and their engagement appeared higher as well. Participants told me plainly that multimedia is expected in a modern online course and that its absence signals a subpar one. The video group also scored lower on the module quizzes, and final examination scores came out close to even.
That result is the most useful thing this study produced. One interpretation is that a summary video can substitute for reading rather than reinforce it, so a learner who watches instead of reading may feel more satisfied while knowing less. It is why I now advise clients that video earns its place when it sends learners back into the material rather than standing in its place. If I ran the study again, I would keep the videos exactly as specified, add a required retrieval task immediately after each one, and watch whether the quiz gap closes.