According to WPC, the letter grades are based on the State Board of Education’s Achievement Index for the school year 2011-12, measuring student test scores in reading, writing, math and science, plus each school’s graduation rate.
“Letter grades are instantly familiar and understandable,” said Liv Finne, director of the Center for Education at the Washington Policy Center. “Governor Inslee has endorsed the idea of letter grades for schools, as have many lawmakers, because parents may easily find out how their child’s school is doing. We show how such a system work would if the Legislature were to officially enact it.”