Given that D.C. has become a Petri dish for Rhee-style reform, every test score release is treated as earth-shattering.

Matthew Di Carlo of the Shanker Institute says not so fast.

Reporting on test scores is far more complicated than it seems, and the public never understands that the setting of the cut scores is a decision made by humans, not a matter of scientific weights and measures.

He writes:

“Until the general public understands that cross-sectional proficiency rate changes are truly poor measures of student progress, and that raw changes, whether cross-sectional or longitudinal, cannot tell us much about whether policies are “working,” officials and advocates on both “sides” will keep firing empirical blanks at each other, in a battle that neither can actually win.”