Remotely controlled robots can expand our research and practice of collaborative learning. Such robots can be used to run a controlled experiment in classroom-like settings by delivering the same information to different groups, so that we can explore the effects of a particular discourse in collaboration. Using this technique, we have tested 25 groups in jigsaw-like, knowledge-constructive collaborative learning situations, with eighty 5th and 6th graders on science topics. There was one robot for each group, which consisted of 2 to 4 children. We have found that (1) children collaborated well among themselves and (2) they could learn well with such robots. We have also found the groups whose talks focused more on the task performed better than those with less focused talks. Currently we are analyzing the protocols to see what kind of intervention by the robots would have the children focus more on the task.