Method
Nine experienced mathematics teachers were randomly organized into two virtual groups: four in the forum
condition and five in the chat condition. A similar pair of sessions was carried out with eight novice
mathematics teachers: four in each condition. Those participants had previously seen the animated stories and
discussed them either in a study group or in a teacher education class. In both conditions, the participants did the
same warm-up activity: viewing a clip from the beginning of a lesson and a clip from the end of the lesson, then
responding questions about what might happen in between, and finally viewing the full story. After that the
forum participants went to a forum in which three threads with questions about three noteworthy moments were
created in advance. The chat participants individually responded to those same questions before joining a chat.
A moderator was available in both conditions.