PBL is a little different from how I traditionally used formative assessments in a math classroom to check for understanding in individuals as they worked through a new concept. I think especially when the project is taking place in a group setting, I need to know not only how the whole group is doing, but how each person is contributing, what are they learning, what skills are they applying, etc. I have had kids do a journal to track individual progress and reflections, pose a question and have them give a short 1 to 2 sentence response, and even rate each others skills as team members.
