John Thompson: New Research Uncovers Fresh Trouble for VAM Evaluations
Guest post by John Thompson.
As more and more schools implement various forms of Value-Added method (VAM) evaluation systems, we are learning some disturbing things about how reliable these methods are.
Education Week's Stephan Sawchuk, in "'Value-Added' Measures at Secondary Level Questioned," explains that value-added statistical modeling was once limited to analyzing large sets of data. These statistical models projected students' test score growth, based on their past performance, and thus estimated a growth target. But, now 30 states require teacher evaluations to use student performance, and that has expanded use of algorithms for high-stakes purposes. Value-added estimates are now being applied to secondary schools, even though the vast majority of research on their use has been limited to elementary schools.
Sawchuk reports on two major studies that should slow this rush to evaluate all teachers with experimental
As more and more schools implement various forms of Value-Added method (VAM) evaluation systems, we are learning some disturbing things about how reliable these methods are.
Education Week's Stephan Sawchuk, in "'Value-Added' Measures at Secondary Level Questioned," explains that value-added statistical modeling was once limited to analyzing large sets of data. These statistical models projected students' test score growth, based on their past performance, and thus estimated a growth target. But, now 30 states require teacher evaluations to use student performance, and that has expanded use of algorithms for high-stakes purposes. Value-added estimates are now being applied to secondary schools, even though the vast majority of research on their use has been limited to elementary schools.
Sawchuk reports on two major studies that should slow this rush to evaluate all teachers with experimental