I often use the small group activity to alert students to the fact that something is subtle or difficult. And I use the class wrap-up discussion to resolve the situation, to get them to see what the correct physics is. Those two pieces may be separated in time. And so it's difficult to show how they go together.

It's important to hold in your head information about what the students' current thinking is about a variety of different topics and so I find myself often going back a few minutes to a few days to even a whole term later and referring back to something that someone was thinking or saying and showing here is a contradiction to that or here is an example that confirms that or here's another way of thinking about that. I think you can't get the kinds of complex understandings that are typical of professional physicists if you always push for resolving understandings within a few minutes. When the students talk about the fact that we 'check in' with them all the time, I expect that in part they are referring to that, coming back over and over again across long periods of time.