Data from Ohio show little relationship between a school's enrollment and its rating on the Ohio school performance index. (educationnext.org)
Well it seems that some mathematical errors were discovered recently in the state's year - old School Performance Index (SPI). (jonathanpelto.com)
In addition, school performance indices typically create summative classifications that are simple to understand, such as A through F letter grades. (americanprogress.org)