The Academic Performance Index (API) is the cornerstone of California's Public Schools Accountability Act of 1999 (PSAA). The purpose of the API is to measure the academic performance and growth of schools. It is a numeric index (or scale) that ranges from a low of 200 to a high of 1000. A school's score on the API is an indicator of a school's performance level. The statewide API performance target for all schools is 800. A school's growth is measured by how well it is moving toward or past that goal. A school's API Base is subtracted from its API Growth to determine how much the school improved in a year.

APIs are reported according to their API reporting cycle. An API reporting cycle consists of two components: (1) base information and (2) growth information. In a reporting cycle, a Base API is compared to a corresponding Growth API in order to determine how much a school's API grew from one year to the next (referred to as API growth). Generally, base reports are provided after the first of the calendar year, and growth reports are provided each August. These reports are based on APIs that are calculated in exactly the same fashion with the same indicators but using test results from two different years.

The API score summarizes the results of various indicators (i.e., statewide tests used in calculating the API). The 2006 Base API uses 2006 statewide test results and the 2007 Growth API uses 2007 statewide test results. Indicators used in calculating the 2006-07 API reporting cycle include:

Standardized Testing and Reporting (STAR) Program

• California Standards Tests (CSTs)
  • English-language arts (ELA), grades two through eleven, including a writing assessment at grades four and seven
  • Mathematics, grades two through eleven
  • History-social science, grades eight, ten, and eleven
  • Science, grades five, eight, and nine through eleven
• California Alternate Performance Assessment (CAPA)
  • ELA, grades two through eleven
  • Mathematics, grades two through eleven
• Norm-referenced test (NRT)
  • California Achievement Test, Sixth Edition Survey (CAT/6 Survey) in reading, language, spelling, and mathematics, grades three and seven

California High School Exit Examination (CAHSEE)

• English-language arts and mathematics, grade ten (and grades eleven and twelve if the student passed the test)

Statewide test results are incorporated into the API calculation according to the amount of weight, or emphasis, given to each test. Each school’s content area weights are determined based on test weights established by the State Board of Education (SBE) and on the number of valid test scores in each content area and grade level at a school. API calculations result in content area weights that may be slightly different for each individual school.

The following tables show the test weights used in the 2006 Base API calculations for the California Standards Tests (CSTs), California Achievement Test, Sixth Edition Survey (CAT/6 Survey), and California High School Exit Examination (CAHSEE). Grades 11 and 12 of the CAHSEE are counted in the API only if the student passed. The test weights shown in these tables do not reflect the content area weights for a school, which will vary based upon these weights and the number of valid test scores in each content area.

Test Weights
Grade Levels Two Through Eight

Note: The Assignment of 200 weight is assigned as scores for students
who did not take the CST in mathematics, grade eight.

Test Weights
Grade Levels Nine Through Eleven

Note: The Assignment of 200 weights are assigned as scores for students
who did not take the CST in mathematics, grades nine through eleven,
or the CST in science, grades nine through eleven.

The API calculation method determines the API as the weighted average of student scores across content areas and tests results within the school. To calculate the API, individual student scores from each indicator are combined into a single number (the API) to represent the performance of a school. For the CSTs, the standards-based performance level (Advanced, Proficient, Basic, Below Basic, or Far Below Basic) for each student tested is used. Performance levels on the CAPA also are included in the API and treated in the same way as CST performance levels. For the CAT/6 Survey (a norm-referenced test), the national percentile rank (NPR) for each student tested is used to make the calculation. For the CAHSEE, a level of pass or not pass is used. A scale score of at least 350 on the English-language arts part or mathematics part of the CAHSEE is considered passing for the API. Each student's test result is assigned a performance level weighting factor of 200, 500, 700, 875, or 1000 based upon the level of the test score, as shown in the following table.

API Performance Level Weighting Factors

Each student’s performance level weighting factor is multiplied by a test weight and summed for all content areas for the school. This sum is divided by the sum of the test weights for the school to produce a single number between 200 and 1000, which is the API for a school. The API is calculated separately for grades two through six, seven through eight, and nine through eleven.

Schools must meet their annual schoolwide API growth target as well as API growth targets for each numerically significant ethnic/racial, socioeconomically disadvantaged, English learner, and students with disabilities subgroup at the school.

If the school's (or subgroup's) Base API is between 200 and 690, the growth target is 5 percent of the difference between the school's (or subgroup's) Base API and the statewide performance target of 800. If the school's (or subgroup's) Base API is between 691 and 795, the growth target is a gain of five points. If the school's (or subgroup's) Base API is between 796 and 799, the growth target is the following:

• API of 796 - a gain of four points
• API of 797 - a gain of three points
• API of 798 - a gain of two points
• API of 799 - a gain of one point

If the school's (or subgroup's) Base API is 800 or more, the school (or subgroup) must maintain an API of at least 800.

A "numerically significant" subgroup is defined as having at least 100 or more students with valid STAR Program scores or 50 or more students with valid STAR Program scores who make up at least 15 percent of the total valid STAR Program scores. Subgroup API information is calculated for the following student categories:

• African American or Black (not of Hispanic origin)
• American Indian or Alaska Native
• Asian
• Filipino
• Hispanic or Latino
• Pacific Islander
• White (not of Hispanic origin)
• Socioeconomically disadvantaged
• English Learners
• Students with Disabilities

These subgroups are defined based upon demographic data from the STAR Program test administration.

• "Socioeconomically disadvantaged" is defined as a student whose parents both have not received a high school diploma OR a student who participates in the free or reduced-price lunch program (also known as the National School Lunch Program).
  
  
• "English learner" is defined as an English learner or as a reclassified-fluent-English-proficient (RFEP) student who has not scored at the proficient level or above on the CST in ELA for three years after being reclassified.
  
  
• "Student with disabilities" is defined as a student who receives special education services and has a valid disability code.

API decile ranks are listed on the Base API reports. Schools are ranked in ten categories of equal size, called deciles, from one (lowest) to ten (highest). There are two types of API ranks: statewide rank and similar schools rank. The statewide rank compares a school to other schools of the same type statewide. The similar schools rank compares a school to 100 other schools of the same type and similar demographic characteristics.

To calculate the statewide ranks, schools' API scores are first sorted separately within school type: elementary, middle, and high schools. For each of the three categories, school's API scores are organized from lowest to highest statewide. This list of school APIs is divided into ten groups of equal size and numbered from one (lowest) to ten (highest). A school's statewide rank is the decile where that school's API occurs compared to other schools statewide.

To calculate the similar schools ranks, schools are separated by school type. Next, a School Characteristics Index (SCI) is determined for each school. A comparison group of 100 similar schools is formed based on similar SCIs. The APIs of the comparison group is organized into deciles from one (lowest) to ten (highest). A school's similar schools rank is the decile where that school's API occurs compared to the 100 other schools in the comparison group.

The PSAA established the API for school level accountability. However, local educational agencies (LEAs) began receiving an API Report as a result of policies established to meet federal No Child Left Behind (NCLB) requirements. An LEA can be a school district or a county office of education. LEAs do not have state-required growth targets and do not receive ranks.

Schools in the Alternative Schools Accountability Model (ASAM) receive an API for federal NCLB purposes only. The ASAM provides state accountability for alternative schools serving highly mobile, high risk students. These schools include community day, continuation, opportunity, county community, county court, California Youth Authority, and other alternative schools that meet stringent criteria set by the SBE. The ASAM is a multiple-indicator system that includes performance and pre- and post-assessment indicators approved by the SBE and state assessment results as summarized in the API. ASAM schools select indicators and report data at the end of each school year. ASAM schools do not have growth targets and do not receive ranks.

Small schools are defined as having between 11 and 99 valid STAR scores for API purposes. Small schools receive an API with an asterisk to denote the greater statistical uncertainty of an API based on small numbers of student results. These small schools are not included in calculating ranks for non-small schools but receive asterisked statewide ranks to indicate the decile rank into which their APIs would have fallen if they had been included in the ranking system. Schools with asterisked APIs do not receive similar schools ranks.

Special education schools receive an API but do not receive API ranks.

API data are used to meet state and federal requirements. Under state PSAA requirements, if a school meets participation and growth awards criteria, it may be eligible to become a California Distinguished School or NCLB-Blue Ribbon School. If a school does not meet its growth targets and is ranked in the lower part of the statewide distribution of the Base API, it may be identified for participation in an intervention program. Under federal NCLB requirements, a school must meet Adequate Yearly Progress (AYP) requirements, which include meeting additional API requirements.