In order to analyse collaboration, one should find specific patterns in participants' interaction. I am still looking for a paradigm for counting gestures. Via Multimodality and Gestures in the Teachers Communication (Giorgio Merola and Isabella Poggi):
A deictic gesture indicates something in the surrounding environment: a way to set the reference of our discourse, then a way to explain what, in the external world, we are going to talk about. An iconic gesture instead describes the shape, size or movements of some referent we are mentioning; and this description can be sometimes metaphorically extended to refer to some abstract referent. Finally, some symbolic gestures directly mention some object, feature or action.