The use of modality in the design of verbal aids in computer-based learning environments

Computer-based learning environments include verbal aids helping learners to gain a deep understanding. These aids can be presented in either the visual or the auditory modality. The problem is that it is not clear-cut how to present them for two reasons: the modality principle [Mayer, R.E., 2001. Multimedia Learning. Cambridge University Press, New York] is not applicable because verbal aids do not usually come with related pictures and the little empirical research on the question provides diverging results. Our aim was twofold: to present a research framework, which makes it possible to reinterpret prior findings, and to test it empirically as it provides guidelines about how to present verbal aids. It distinguishes between two types of verbal aids: regulatory, which guide the learners’ decision making process during learning, and explanatory, which help learners to revise their understanding of the to-be-learned contents. The framework suggests that explanatory aids should be presented visually and regulatory aids should be presented auditorily. In two experiments participants learned from a computer-based learning environment on plate tectonics and solved retention and inference questions afterwards. They received verbal aids presented in different modalities depending on the condition. Participants receiving visual explanatory aids outperformed those receiving auditory explanatory aids both in retention and inference questions. Participants receiving auditory regulatory aids showed no advantage; the same pattern was obtained in the second experiment, in which the auditory aids were given by a pedagogical agent. Results have practical implications for the design of computer-based materials.