Modality Matters: How Text, Audio, and Video Interactions Shape Student Engagement and Performance with AI Tutors in 6–8 Mathematics

As AI tutoring systems are tested for use in K-12 classrooms, understanding their effects on learning and how interaction modality shapes student engagement is essential. Across three studies, students could ask for help from a generative AI tutor chatbot which responded in a text, audio, or video format during classroom math lessons. In the text modality, students experienced a typical text-only chatbot experience. In audio and video modalities, text was still present but each message was read aloud by an AI-generated voice and, in the case of video, accompanied by a human-like AI-generated avatar. In Study 1, we collected qualitative feedback on each modality. In Study 2, students were randomly assigned to one modality as they worked through solving math problems as part of normal course work. In Study 3, students were assigned a default modality but had the agency to switch modality. Results indicated a clear preference for text. Although initial engagement was higher in the audio condition, students frequently switched to text when given a choice. Student feedback and behavior also showed an aversion to the video modality. When modality was assigned, performance was also lowest in the video condition. However, when students could choose their modality, these differences disappeared. Instead, students who exercised agency over the modality engaged in longer conversations with the tutor, and the increased engagement fully mediated the effect of agency on accuracy. These findings suggest that giving students agency over modality can support sustained interactions with an AI tutor leading to higher performance.