Methods for Accounting for Co-Teaching in Value-Added Models (Journal Article)

Key Findings:

• States and school districts have an interest in adapting their teacher evaluation systems to account for students being co-taught by multiple teachers. 
• We assess three methods for incorporating information about co-teaching into value-added models of teacher effectiveness.
• One method attempts to identify how the amount of time spent with each separate co-teacher contributes to student learning, but practical problems may limit its usefulness.
• The other two methods assume that co-teachers have joint responsibility for their shared students. These methods produced similar results, but one of them (the “Full Roster Method”) can be more easily implemented in practice.