The P Scales are a set of criteria or performance descriptions "...for measuring the progress of pupils for whom the early levels of the National Curriculum are not appropriate."

"The performance descriptions have been written for use with pupils of all ages and with a range of special educational needs. The descriptions are not a full description of all that pupils might achieve. They are intended to provide a framework on to which the progress of pupils, measured using the school's own assessment scheme, can be mapped. The descriptions do not replace the more finely tuned assessment schemes used for detailed individual assessments and curriculum planning by many schools. Rather, they complement those schemes by providing a common basis for comparing performance between pupils and schools." (DfES, 2001)