Audrey Amrein-Beardsley is one of the nation’s leading experts on value-added assessment. She is also one of its most prominent critics. In her blog VAMboozled, she follows the ongoing damage done by VAM to teachers and schools across the nation.

 

In this post, she draws attention to the findings of one of her graduate students, Jessica Holloway-Libell, who studied the use of VAM in Tennessee. Tennessee has employed a VAM model since the early 1990s based on the work of agricultural statistician William Sanders. Jessica’s study has been published in the peer-reviewed Teachers College Record.

 

Jessica found “Evidence of Grade and Subject-Level Bias in Value-Added Measures,” the title of her article.

 

Amrein-Beardsley writes:

 

More specifically, Jessica found that:

 

Teachers of students in 4th and 8th grades were much more likely to receive positive value-added scores than in other grades (e.g., 5th, 6th, and 7th grades); hence, that 4th and 8th teachers are generally better teachers in Tennessee using the TVAAS/EVAAS model.

 
Mathematics teachers (theoretically throughout Tennessee) are, overall, more effective than Tennessee’s English/language arts teachers, regardless of school district; hence, mathematics teachers are generally better than English/language arts teachers in Tennessee using the TVAAS/EVAAS model.

 

Are teachers of fourth and eighth grades better than all others; are math teachers better than English teachers?

 

Amrein-Beardsley concludes that these findings are additional evidence that Sanders’ VAM is inaccurate and biased towards certain grades and subjects.