The California Department of Education (CDE) has released the updated 2006 Academic Performance Index (API) scores for California schools, including data for San Mateo County and Santa Clara County.  The API is a statewide benchmark based on standardized achievement tests which is primarily used to rank schools relative to one another and relative to schools with similar demographics.  Here's an example of what the statistics look like.

We'll take a look at how school rankings and Silicon Valley real estate prices are related, but first let's look at how to read the information. 

Number of Students.  In the first column, you'll find the number of students whose results were included from that school.  It's pretty close to the total number of students, less any excluded students.  The rules for excluding students are listed in the API Base Documentation Information Guide found on the CDE API page.  Surprisingly, the number of students has little to do with how well the school did in its API scores (almost, see epilogue).

Base API, Statewide Rank, Similar Schools Rank.  The Base API score is like an SAT score except it's from 200 to 1000.  Higher is better.  To make comparing schools easier, the CDE provides a statewide rank from 1 to 10 (ten is best) and a similar schools rank that rates schools (again from 1 to 10, ten being best) that have similar demographics and characteristics.  Apples-to-apples in a way.

Growth Target, API Target.  The growth target is the number of points California wants the school to improve in the next year.  That added with the current base API score equals the API target.  The CDE doesn't set a target for schools above the current statewide performance target of 800.

(c) Steve Leung for the Silicon Valley Real Estate Blog at 1SiliconValley.com

Reading California School Ranking (API) Scores