The use of value-added modeling (VAM) in school accountability is expanding, but deciding how to embrace VAM is difficult. Various experts say it's too unreliable, causes more harm than good, and has a big margin for error. Others assert VAM is imperfect but useful, and provides valuable feedback. A closer look at the models, and their use,…

Value-added models have become popular fixes for various accountability schemes aimed at measuring teacher effectiveness. Value-added models may resolve some of the issues in accountability models, but they bring their own set of challenges to the table. Unfortunately, political and emotional considerations sometimes keep one from examining…

The Teacher Assessment Project at Stanford University focused on both simulation exercises and portfolios. Although portfolios are messy to construct, difficult to score, and vulnerable to misrepresentation, they provide a connection to the contexts and personal realities of real teaching and help document teaching and learning over time.…