CCCCO Percentage Point Gap Minus One (PPG-1) Methodology Notes [2022]

This document presents an overview of the percentage point gap minus one (PPG-1) method which can be used to examine disproportionate impact (DI), with guidelines to better understand the disaggregated subgroups that are significantly impacted. This method can be applied to assess disproportionate impact across a variety of indicators, including those in the Student Success Metrics, successful course completion, ESL & basic skills completion, degree and certificate completion, transfer, and others.

Disproportionate impact occurs when a subset of students based on a student characteristic such as age, race, or gender have observably different outcomes when compared to the total student population. The Chancellor’s Office seeks to ensure policies and practices are not designed in ways that impede or interfere with or differentially support student progress or success for a given student population. Over the past few years, colleges have used various methods to measure disproportionate impact; but due to the passage of AB 504, the California Community Colleges are legislatively mandated to use at least one common methodology across all colleges and districts. Additionally, using one method across all the colleges in the system will make it easier to measure the magnitude of issue system wide and track our efforts to equity gaps in our outcomes.