Here's a reasonable set of ground-rules. Failure to understand and follow these rules will constitute cheating, and will be dealt with as per university guidelines. This applies when the assignment is supposed to be an individual effort. This will assure that you are able to reconstruct what you learned from the meeting, by yourself, using your own brain. Failure to adequately acknowledge your contributors is at best a lapse of professional etiquette, and at worst it is plagiarism.
Plagiarism is a form of cheating.
We want to know about dysfunctional group situations as early as possible. To encourage everyone to participate fully, we make sure that every student is given an opportunity to explain and justify their group's approach.