As a result of ABET's EC 2000 Criterion 3, outcome (d), "an ability to function on multidisciplinary teams" 1 this multi-university research team has focused its attention on teamwork and how it is assessed. Teamwork in engineering is often assessed using a peer evaluation instrument. It is not always clear, however, what characteristics of teamwork these instruments, or the students, are evaluating. In preparation for this multi-year NSF-supported project, the team reviewed peer evaluation literature and instruments. The research team has an ambitious assessment plan that will help develop an instrument that is easy to use and yet meaningful for both faculty and students.