Hi! When ever I have a group of 3 I let the kids know that when I switch them they'll have to make sure everyone gets a turn.
The other thing I do is "tag-team" (which I 'borrowed' from another WB teacher). I still say "Teach", the students say "Okay" but instead of me saying "switch", the students high five and say "tag team" to switch themselves. This will allow them to make sure all 3 of the partners get to share their ideas and thoughts. I also make sure students know that they can tag team multiple times before I call them back to the group, this way they don't tag team once and then sit there.
I hope this helps.
Tiffany
WBT Intern, 2011-2012
mywholebrainteachingjourney.blogspot.com/