Van Merriënboer (2001) noted with regret that little is known about the optimal combination of audio, screen texts and illustrations in pictures or video. In fact there are some substantial papers at the macro-level, by educational technologists such as Laurillard and Taylor at the UK Open University. These do address some design techniques, which appear below, but mainly they discuss global questions, such as how learners might cope without a fi xed linear narrative (Laurillard 1998; Laurillard et al. 2000) and how to describe multimedia learning systems using an analytical framework (Taylor et al. 1997). However, the literature appears to lack any comprehensive framework of micro-level design principles for optimal integration of visuals and audio. This is despite the many investigations into the use of audio commentary in multimedia presentations. Some of these investigations are summarized below, confi rming mixed results in the comparison of screen text with audio commentary.