There is some empirical evidence suggesting that what students do in the tutorial group is indeed attempting to construct a mental model or ‘‘theory’’ that explains the phenomena described in the problem. For instance, he showed students videos of their own contributions to a tutorial discussion and asked them to recall what they were thinking. This stimulated recall procedure in combination with verbatim transcripts of the verbal interaction in the group suggested that indeed theory building, and to a lesser extent, data exploration and hypothesis evaluation were central to the thoughts and verbal utterances of the students.