This article was originally published in The Notebook. In August 2020, The Notebook became Chalkbeat Philadelphia.
The District’s press release said that about half the schools ended up with different scores, but most of those were off by just a point on the 10-point scale. SPI scores have figured into many high-stakes decisions, such as determining which schools to close or convert to charters.
The years in question included those in which widespread adult cheating on state standardized tests has been investigated. But Superintendent William Hite’s statement said that "the underlying data feeding into the SPI was not in question nor considered to be faulty." Rather, "the calculation used to produce the SPI scores for traditional public and charter schools was in question."
The biggest error was "inconsistencies" in calculating the "growth measure" for the PSSA, which rates how well a school did in improving students’ scores from one year to the next and accounts for a significant portion of the overall score.
The District hired an outside consultant to rethink and revise the entire SPI process, and has yet to release SPI scores for 2012. Charter schools in particular had complained about the measure.
Around the time that it announced the errors in SPI, the District’s head of accountability was fired, but officials would not comment on whether there was a connection.