The central claim contained in this paper is that grounding is the process happening at the utterance and collaborative level. They say that when collaboration and grounding take place with respect of a specific level/object, then the two coincide. However, grounding and interaction may take place with respect to different levels/objects simultaneously in a given situation. In this case, there can be both collaboration and non-collaboration, but with respect to different levels/objects.
In another point, they say that grounding take place at semantic and pragmetic levels. At the semantic level, grounding involves searching for common understanding of refferent and meanings of terms. At the pragmatic level, grounding involves, for example, interactional participants understanding each others’ communicative intentions.
Their view on how grounding and collaborative learning are interrelates is summarised as follows: collaborative learning will be associated with gradual transition from the use of language as a medium for grounding communication (pragmatic) to grounding on the level of the medium itself (semantic), leading to the appropiation of the medium.
Another interesting point is that, for measuring grounding in collaboration they start looking at actions in their framework for modelling energy in physics (C-CHENE). Lastly, here Baker states that grounding can be assimilated to negotiation.