The Disfluency Effect Revisited: Why Audiovisual Channel Manipulations Impair Motivation and Trigger Illusions Without Boosting Learning

ABSTRACT Background Previous research on multimedia learning has predominantly applied perceptual disfluency consistently across both visual and auditory channels within instructional materials. Such dual‐channel disfluency may impose excessive extraneous cognitive load (ECL), thereby undermining learning outcomes. The disfluency effect, however, posits that perceptual disruptions to processing fluency can, under specific conditions, facilitate learning. Nevertheless, empirical evidence regarding the efficacy of disfluency manipulations in audiovisual learning environments remains inconclusive. Objectives This study investigated whether a more nuanced application of disfluency, as a means of cognitive load manipulation, can yield positive effects in video‐based learning. Specifically, we examined how progressively reducing ECL through controlled disfluency manipulations influences learning performance, metacognitive judgements (judgements of learning), learning motivation and subjective learning experiences. Methods Experiment 1 examined the effects of varying degrees of disfluency in audiovisual channels (fully fluent, partially disfluent, fully disfluent) on multimedia learning outcomes ( n = 48). Experiment 2 built upon these materials by further attempting to mitigate ECL through the separation of visual and auditory disfluent information. It employed a 2 (channel: visual channel; auditory channel) × 2 (fluency: partially disfluent; fully disfluent) between‐subjects design ( n = 109). Results and Conclusions Results from Experiment 1 indicated that, although disfluency manipulations in audiovisual channels increased ECL, they reduced learning motivation and induced metacognitive overestimation, while having no significant effect on learning performance. In Experiment 2, all four experimental groups showed significantly higher ECL than the fully fluent dual‐channel group, whereas learning performance remained unaffected. Disfluency also led to metacognitive overestimation and a significant decrease in learning motivation across conditions. Overall, these findings do not support the disfluency effect in video‐based learning. Rather than enhancing learning performance, disfluency was associated with inflated metacognitive judgements (illusions) and reduced learner motivation.