I also thought this video was interesting. With larger numbers I suppose the same principles apply in that we need to value diversity and look for ways of promoting the strengths of the students. I like the idea of the students providing some information about themselves so that they become more 'real' to one another. I wonder if you could devise an activity which gives the students an opportunity to learn something about each other as a starting point. It must be difficult with such a large group to promote individual identity.
Large classes are becoming more common and so this is an important topic. You said that you have some Chinese students, but you haven't mentioned what other cultures make up your class.
The video really hits home for me and it seems like the exact same thing happens in my classess. I've found with my culturally diverse classes that more direction in how to form the groups is always beneficial - team work designs that give each person a specified and active role can help. When learners know exactly what's expected of them, they tend to be more comfortable.
I've recently been much more prescriptive about how I establish learning sets membership (these are course-long study groups) and I've spent a good deal of time attempting to make each group is as diverse as possible. I use all of the knowledge I have about the students, plus some of my own presumptions and assumptions, to mix them up. It takes me more than an hour for 20 or so students, but it's an investment of time that has been very worthwhile.
For shorter activities I often ask learners to pair with someone they have never spoken to before (you saw me do that last week :-)), or I will group people using cross-overs where, say, 6 groups of 5 become 5 groups of 6. With pair work, everyone is participating. These kinds of activities can be done with a class of any size.
I hope this is helpful.
Viv (Plymouth, UK and sometimes BC, Canada)
I tend to vary between directed groups, random ones & self selected. I think it depends on the nature of the task; the proportion of marks they're going to get for the group element vs. the individual element of the task, how long the task is going to take etc.