This article describes an efficient peer evaluation process that can be implemented at the middle and high school levels, and that holds students accountable for their individual contributions in a team-based project. Teachers faced with this challenge will welcome the web-based peer-evaluation interface that was capable of soliciting student ratings of teammates and summarizing the numerical data for use in the grade book as a modifier to the group grade. The assessment instrument: "The Comprehensive Assessment for Team-Member Effectiveness" (CATME) facilitates evaluation on one or more areas: Contributing to the team's work, Interacting with teammates, Keeping the team on track, Expecting quality, and Having relevant knowledge skills and abilities. Each of these areas includes a description of behaviors students can identify in their peers. Language used in the student interface is easy to understand and will require little explanation for high school students. The rating system describes behaviors exhibited by teammates, which helps keep the focus on team contribution instead of student popularity. Teachers can use this insight about team performance to mentor students and help them resolve issues within their team.