Results get sent around a group of biological collaborators for feedback. Comments come back from the senior members of the group about the implications of the results, possible extensions, etc. I look at the results and I tend not to be as good at the "big picture" stuff (I'm a relatively junior member of the team), but I'm reasonably good with statistics (and that's my main role), so I look at the details.

Sometimes I think to myself "I don't think those conclusions are remotely justified by the data". How can I give honest feedback in a way that doesn't come across as overly negative? I can suggest alternative, more valid approaches, but if those give the answer "it's just noise", I'm pouring cold water over the whole thing.