Abstract:

In recent years, short videos have attracted widespread attention and have been increasingly adopted in education as an innovative pedagogical tool. Prior research suggests that both the effective application of multimedia learning principles and the inclusion of teachers’ positive emotional expressions can enhance learners’ experiences. However, little is known about how these two design features interact to shape learners’ emotional engagement, especially within short video environments.

To address this gap, we searched TikTok using the keyword “English pronunciation learning” and retained all videos published in 2023 that appeared in the search results (n = 49). Each video was evaluated based on:
(a) the total number of multimedia learning principles implemented,
(b) the level of instructors’ facial positivity detected using a JavaScript-based convolutional neural network, and
(c) the mean emotional valence of user comments estimated using a pre-trained Transformer language model.

Moderation analysis revealed a significant interaction between multimedia learning principles and facial positivity in predicting comment valence (b = 0.093, SE = 0.023, Z = 4.012, p < .001), whereas neither multimedia learning principles nor facial positivity showed a significant main effect. Simple-slope analyses indicated that when facial positivity was low, the use of multimedia learning principles predicted more negative comment valence (b = –0.014, p = .046). When facial positivity was at an average level, this relationship was not significant (b = 0.004, p = .502). When facial positivity was high, the relationship reversed direction and became significantly positive (b = 0.022, p = .004).

In summary, the findings demonstrate that multimedia learning principles positively influence viewers’ emotional responses only when instructors exhibit high facial positivity. This moderation effect highlights the importance of integrating instructors’ positive affect into the design of short educational videos.

Keywords:

Short video, multimedia learning principles, facial positivity, emotional engagement.