  The effects of social groups on pedestrian dynamics, especially in evacuation
scenarios, have attracted some interest recently. However, due to the lack of
reliable empirical data, most of the studies focussed on modelling aspects. It
was shown that social groups can have a considerable effect, e.g. on evacuation
times. In order to test the model predictions we have performed laboratory
experiments of evacuations with different types and sizes of the social groups.
The experiments have been performed with pupils of different ages. Parameters
that have been considered are (1) group size, (2) strength of intra-group
interactions, and (3) composition of the groups (young adults, children, and
mixtures). For all the experiments high-quality trajectories for all
participants have been obtained using the PeTrack software. This allows for a
detailed analysis of the group effects. One surprising observation is a
decrease of the evacuation time with increasing group size.
