California has for many years used the Academic Performance Index (API) to measure the progress of students and schools. The federal No Child Left Behind Act (NCLB) requires that students and schools meet standards called Adequate Yearly Progress (AYP), and that states have a second method for measuring achievement. California uses the API as that second measurement.

Summary of AYP by Gladys Frantz, Director of Curriculum and Instruction, Alameda County Office of Education (Available in PDF or Flashpaper format)

API information from the California State Department of Education

AYP information from the California State Department of Education

API/AYP information from the Alameda County Office of Education