Beyond Disaggregation: Identifying Equity Gaps by Measurement of Disproportionate Impact
This project seeks to disaggregate data by sub-group and utilize the Proportionality Index (PI) methodology for assessing disproportionate impact to appropriately measure progress attained by strategies or interventions to close equity gaps.
Identify Equity Gaps
4-Year Institution
John Carroll
Associate Director, Institutional Research
Ryan Khamkongsay
Director, Institutional Research and Effectiveness
Pooja Malviya
Institutional Research and Effectiveness Research and Reporting Analyst

Disproportionate impact occurs when a subset of students based on various characteristics (e.g., age, race, gender, economically disadvantaged, etc.) are unjustifiably experiencing lower outcomes compared to the overall student population. Therefore, a DI group may need more access to student services and support to reach success outcomes at rates similar to other groups.

The Proportionality Index (PI) methodology will be used to indicate that disproportionate impact exists. The formula for calculating proportionality index is the percentage in the outcome group divided by the percentage of the overall population. At TAMUCT, the IRE office has designated an index of 0.8 to be the proxy to determine if a subgroup is disproportionately impacted.


TAMUCT/s Institutional Research & Effectiveness Office (IRE) will adopt an evidence-based practice for identifying and measuring equity gaps among disproportionately impacted student groups. This methodology requires IRE members to utilize TAMUCT's Student Success Dashboards as the initial source of data for various student success indicators of the overall student population in order to establish a baseline. Our researchers will then disaggregate the data by sub-groups and utilize the Proportionality index (PI) methodology for assessing if disproportionate impact (DI) exists among sub-groups of students. This approach allows for proper measurement of progress attained by strategies or interventions that the university will undertake to close equity gaps.

Lessons Learned

Implementation of this project led to the following plans for scaling and sustaining the work:
The IRE Office plans to incorporate out calculations for determining disproportionate impact of student sub-groups in existing student success dashboards. This process will be embedded as part of our annual standard operating procedures to allow end-users the ability to go one step beyond traditional data disaggregation and strengthen practices of establishing realistic targets and benchmarks. Outreach and intervention planning that target these sub-groups of students should be cross-functional based on the experience of support staff and faculty in their direct work with students.