While team work is an indispensable experience for computer science students, evaluating their performance in a project becomes a great challenge for the instructors. The basic assumption in a collaborative work is that each member of the collaboration has something to contribute. It is assumed that no member of the team is non functional. But how do we measure the contribution of each member of the team? An effective documentation tool is helpful. In this paper, we discuss why we need such a tool through a case of an open source software-based project in a computer science course. We then propose an annotation model AMIESDev (Annotation Model for Information Exchange Software Development) to assist in evaluation of students' contribution in a collaborative work. The model can also be used to monitor the progress in the work.