CDLA · Module 2 — Learning science for digital media
Strip material that does not serve the objective. Do not narrate the same sentences you already printed. Keep captions.
About 18 min
Practice in the lesson player
Sorting, matching, quizzes, and the module gate stay behind a free account so scored answers are not public. The teaching notes below are the same cited curriculum.
01
Coherence (median d = 0.70): remove material that does not serve the goal, including interesting stories, background music and extra detail. Redundancy (median d = 0.87): do not add the same words as on-screen text to a narrated graphic. Both protect working memory. More explanation is not automatically more learning.
02
WCAG requires captions for prerecorded video with audio. That is an access requirement, not a breach of the redundancy principle. The research compared adding the same words as on-screen text for learners who can already hear the narration. Offer captions as a track the learner can switch on, not as a paragraph printed on the screen.
03
Interesting but irrelevant additions are called seductive details. A meta-analysis by Sundararajan and Adesope (2020) found that, on average, they lower both retention and transfer. For bilingual courses there is a related trap: printing the English sentence on screen while the narration is in Arabic. That is not redundancy in the research sense, but it is split attention for most Arabic-first learners. Choose one language per screen for running text, and keep labels in the language of the narration.
04
In your review module, list every element you would cut under coherence or redundancy, with the minutes it would save. Add the total to your design review. Sponsors respond to minutes saved per learner multiplied by headcount.