During the past two terms I have had small groups of students who probably were placed in classes prematurely when they had not yet taken classes which would have benefitted them for the course there were enrolled in. I find it more complicated to bring them up to speed, especially when most of the others in the class are at a more advanced stage of their programs. I tried an "experiement" two terms ago which seems to be working. I've paired the less experienced studenst with a more experienced student to be a class mentor. That has seemd to pay off for the whole class and has helped bring the less experienced students up to a higher level sooner.