In a post last week over at Flypaper, the Fordham Institute’s Terry Ryan took a “frank look” at the ratings of the handful of Ohio charter schools that Fordham’s Ohio branch manages. He noted that the Fordham schools didn’t make a particularly strong showing, ranking 24th among the state’s 47 charter authorizers in terms of the aggregate “performance index” among the schools it authorizes. Mr. Ryan takes the opportunity to offer a few valid explanations as to why Fordham ranked in the middle of the charter authorizer pack, such as the fact that the state’s “dropout recovery schools," which accept especially hard-to-serve students who left public schools, aren’t included (which would likely bump up Fordham's relative ranking).
Mr. Ryan doth protest too little. His primary argument, which he touches on but does not flesh out, should be that Ohio’s performance index is more a measure of student characteristics than of any defensible concept of school effectiveness. By itself, it reveals relatively little about the “quality” of schools operated by Ohio’s charter authorizers.
But the limitations of measures like the performance index, which are discussed below (and in the post linked above), have implications far beyond Ohio’s charter authorizers. The primary means by which Ohio assesses school/district performance is the state’s overall “report card grades," which are composite ratings comprised of multiple test-based measures, including the performance index. Unfortunately, however, these ratings are also not a particularly useful measure of school effectiveness. Not only are the grades unstable between years, but they also rely too heavily on test-based measures, including the index, that fail to account for student characteristics. While any attempt to measure school performance using testing data is subject to imprecision, Ohio’s effort falls short.