BOULDER, CO (January 30, 2018) – Measures of socioeconomic status (SES) are widely used in educational research and policy applications, in large part due to overwhelming evidence linking SES to student achievement. SES is usually conceptualized as an unobservable factor—a construct—measured using variables such as parental education, occupation, income/wealth, and home possessions to take into account disparities between students, classrooms, and schools.
The National Education Policy Center released a brief today that examines the usefulness of common SES measures. Researchers and policymakers agree on the importance of SES in educational settings, but the available measures that we use belie that importance.
Professor Michael Harwell of the University of Minnesota authored the brief, titled Don’t Expect Too Much: The Limited Usefulness of Common SES Measures and a Prescription for Change. He explores the factors that undermine the usefulness of common SES measures in ways that can bias or muddy research and policy conclusions, and he considers what changes might promote a deeper understanding and more effective use of SES in research and policy.
Professor Harwell’s recommendations include the following:
- A theory-grounded model of SES should be adopted to define this construct in ways consistent with the purpose of the research or policy application.
- Correlations between SES measures and outcomes should be examined to assess the usefulness of these measures as control variables in statistical analyses.
- Researchers and policymakers wishing to employ existing SES measures should consider a composite index of SES, perhaps in conjunction with common measures, or turn to alternative measures such as either students’ perception of their SES or poverty estimates at the district level. Those interested in developing new measures should use a theory-grounded SES model as a guide to help ensure new SES measures do in fact measure what they are intended to (i.e., show evidence of construct validity).
- The development of new SES measures guided by a theory-grounded model of SES requires assembling a multidisciplinary team with expertise in a substantive area of education (e.g., mathematics education) as well as expertise in psychometrics, statistics, and the SES literature.
- Eligibility for a free- or reduced-price lunch should not be used as a student-level SES measure, but aggregating this variable to reflect the percentage of students receiving subsidized meals produces a crude but useful index to compare the economic need of a school or district with other schools or districts.
Find Don’t Expect Too Much: The Limited Usefulness of Common SES Measures and a Prescription for Change, by Michael Harwell, at: http://nepc.colorado.edu/publication/SES