Testing in California: An overview
Academic Performance Index
The purpose of the Academic Performance Index (API) is to measure the year-over-year growth in academic performance for California schools. The API summarizes a school's standardized test results into a single number. Each school's STAR and CAHSEE results are calculated into a complex formula that assigns the school an API between 200 and 1000 (1000 being the best score). The state has set 800 as the target API score that schools should try to achieve. Each API cycle includes a Base API and a Growth API. The Growth API is calculated using test results from the year after the results used in the Base API calculation. Comparing the Growth to the Base API measures the academic growth from one year to the next.
The API number is translated into a ranking, 1 to 10, from underperforming to high performing. It is used to help schools track their own progress and to hold schools accountable for improvement. The API is an important metric because schools that consistently fall short can be subject to strong local or state sanctions, including reorganization or closure. Schools also can be eligible for recognition through the California Distinguished Schools Program. So it's important to pay attention to the API, as this number may have a big impact on your school's future.
Base API
The 2008 Base API was calculated using each school's test results from the state's Standardized Testing and Reporting (STAR) program and the California High School Exit Examination (CAHSEE) taken during the 2007-2008 school year. The California Department of Education releases the Base API results each spring. The Base API is used to measure academic improvement from one year to the next by comparing it to the Growth API released the following summer.
Growth API
The 2009 Growth API will be calculated using the same test criteria as the 2008 Base API. However, the 2009 Growth API was calculated from the 2008-2009 standardized test results, while the 2008 Base was calculated using the 2007-2008 test results. The Growth API is used as a measure of improvement in academic performance when compared to the Base API.
API Growth targets
Each school is assigned an API Growth target by the state. The Growth target is determined by calculating 5% of the difference between the Base API and 800, or a minimum of 5 point growth. Schools with APIs at or above 800 must maintain a minimum API of 800. A school meets its overall API Growth target if it meets its schoolwide target and all numerically significant subgroup targets. Growth targets for subgroups are generally 80% of the schoolwide target.
Improvement is measured by subtracting the 2008 Base API from the 2009 Growth API. Positive numbers mean that standardized test results improved, while negative numbers indicate that test results declined.
API subgroups
Numerically significant subgroups are defined by the state as having at least 100 students in the group who have valid test results or when there are 50 or more such students and they constitute at least 15% of all tested students. Subgroups include the following ethnic and socioeconomic categories: African American or Black (not of Hispanic origin), American Indian or Alaska Native, Asian, Filipino, Hispanic or Latino, Pacific Islander and White (not of Hispanic origin), plus socioeconomically disadvantaged. Students are categorized as socioeconomically disadvantaged if they participate in the federal free and reduced-price lunch program or if their parents did not graduate from high school.
Statewide rank
The California Department of Education ranks all schools from 1 to 10 according to their Base API. A rank of 10 means that the school's API fell into the top 10% of all schools in the state at the same grade level. The most recent ranks are based on the results of standardized tests taken in spring 2007.
Similar Schools Rank
The API Similar Schools Rank compares the test score performance of schools with comparable demographic profiles using a scale of 1 to 10. A school with a low API but high Similar Schools Rank may be more effective than a school with low ranks all around.
The California Department of Education calculated the Similar Schools Rank by comparing each school to 100 schools with similar demographic factors, including parent education levels and the percent of students receiving a free or reduced-price lunch.
Why do the API results matter?
As a fundamental part of the Public Schools Accountability Act (PSAA), API scores are used to meet state and federal requirements for school accountability and are an important component for measuring a school's Adequate Yearly Progress (AYP) under the federal No Child Left Behind (NCLB) Act. These ratings can have substantial consequences for schools. Underperforming schools are given additional funds to encourage improvement and high-ranking schools may be eligible for additional acknowledgment.
It is important to be aware of both your child's score on the assessments and the overall score for his school. If your child scores below the standards, contact his teacher to discuss getting additional assistance, and to find out how you can support your child's learning at home. If the school's overall scores are low, ask what steps the school is taking to raise achievement levels for all students, and what you as a parent can do to help.
Why do some schools not have APIs?
There are several reasons why some schools don't have API results. For example if a school failed to test at least 85% of eligible students or if the school tested fewer than 11 students, the state does not calculate an API for that school. Schools that serve specific kinds of students, such as special education schools, are currently accountable under a different model.

