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Growth Model

Explanation and resources for the student-level growth model.

Overview

Since 2015, California has invested significant time and effort in developing a student growth model that is valid, reliable, and fair. California conducted a thorough and thoughtful process of selecting the model that best meets California's needs. On May 12, 2021, the State Board of Education (SBE) approved a student-level growth model using grades four through eight growth scores. The development and adoption of this growth model was accomplished due to the valuable input from a broad range of stakeholders, and the expertise of the California Department of Education's (CDE's) assessment vendor, Educational Testing Service (ETS), and the Technical Design Group (TDG).

California's Student-Level Growth Model Methodology

Use residual gain* scores for individual student growth and the Empirical Best Linear Predictor (EBLP)** hybrid approach to report aggregated student growth scores.

Report the EBLP weighted average growth score for:

  • Schools
  • Student groups in a school
  • The "All" student group in an local educational agency (LEA)
  • Student groups in a district with 500 or fewer students (with test scores)

Report the simple average growth score at the LEA level for all race/ethnicity and program participation student groups with more than 500 scores.

*Residual Gain (RG) is a way of measuring students' growth between the current year and the previous year, which is the difference between the students' expected test score and their actual test score. A student's expected test score is based on the typical score of students who had similar prior test scores in English language arts/literacy (ELA) and mathematics in the previous grade.

** Empirical Best Linear Predictor (EBLP) was developed by experts in measuring student growth from ETS in response to low year-to-year stability found in one year of aggregated residual gain scores (simple average) and to increase the accuracy of the scores. The EBLP uses a weighted average for two years of growth scores (i.e., three years assessment results) at the LEA, school, and student group levels. However, a simple average growth score works well when it’s based on many student scores. Therefore, a simple average is used for student groups with more than 500 growth scores in an LEA.

A growth score of 100 means that the average student in the school grew as expected. A score of less than 100 means that the average student grew less than expected and a score or more than 100 means that the average student grew more than expected.

For a complete and in-depth technical review of the growth model methodology, the residual gain, and the hybrid EBLP methodology, please view the resources made available at the end of this web page.

Data Release Tentative Timeline

Note that the following timeline is subject to change.

  • June 14, 2021:
    • Release student-level growth data to LEAs via the Test Operations Management System (TOMS).
    • Private preview of aggregate LEA, school, and student group growth data files. (The growth data is based on student performance on the California Assessment of Student Performance and Progress [CAASPP] for ELA and mathematics administered during the 2016–17, 2017–18, 2018–19 school years.)
    • Statewide webinar for Accountability, Dashboard, and California Assessment of Student Performance and Progress (CAASPP) Coordinators on information regarding the student growth data.
  • July 12, 2021:
    • Public release of aggregate LEA, school, and student group growth data via downloadable data files. (note: this release was originally scheduled for June 22, 2021.)
    • These data files are being released for informational purposes only. They are not intended to be used for accountability and evaluation purposes.

Ongoing Work

  • July 2021 through November 2022:
    • Work with LEAs and stakeholders on communication and data use strategies.
    • Develop a report that displays English Language Proficiency Assessment for California levels with growth scores.
  • Fall 2024:
    • Earliest release of the next growth model data using current ELA and mathematics data (i.e., 2022, 2023, and 2024 results).
    • Eventually, the growth model may be incorporated into the California School Dashboard Academic Indicator. This is a decision that will need to be approved by the SBE in future years.

Resources

  • May 2021 SBE Item (DOCX) includes detailed information on the approved growth model methodology and the aggregated growth scores for student groups at the LEA and school-levels.
Questions: Academic Accountability Team | aau@cde.ca.gov | 916-319-0863 
Last Reviewed: Monday, June 21, 2021
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