Undergraduate Science Education: The Impact of Different College Environments on the Educational Pipeline in the Sciences

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Astin and Astin use longitudinal data on over 27,000 college students at 388 colleges to conduct a comprehensive study on an array of factors that affect interest and persistence in science. The authors find that entering academic credentials (particularly in math) are consistently the strongest predictor of students’ persistence in science. Credentials are also good predictors of initial interest in science. Pre-admissions credentials are also the strongest predictors of performance on the GRE and MCAT tests, suggesting that post-graduate performance is largely constrained by pre-collegiate credentials.

The authors were surprised to discover that African American and Hispanic students were more likely to intend to major in hard science than white students.  But these racial groups have much higher rates of attrition during college than white so that the proportion actually receiving science degrees is a little higher for whites than the under-represented minorities. The authors are not able to explain why underrepresented minority groups suffer such large losses of attrition. (Pg. 50-51.) But students leaving the sciences tend to achieve lower grades. However, the post-graduation outcomes (GRE and MCAT scores) reflect large racial disparities. African-American students perform less well on these tests than would have been expected from their pre-college credentials. So the test score gaps that already exist between African-Americans and their white peers at the beginning of college are widened at the end of college.

The authors find that freshmen with a greater proportion of science major friends are significantly more likely to persist in their science major. This peer effect is the largest of the environmental effects that the authors studied. The manner in which science is taught also has large effects on persistence in science during and after college, as the schools that encouraged self-directed research and teaching assistance produced students more likely to stick with science. Written student evaluations also seem to keep students on track.

SEAPHE Comments

This study predates the serious and organized study of mismatch, so the authors did not take into consideration how a student’s SAT-Math scores and other important predictors relative to their peers affects persistence in science. Circumstantial evidence corroborates mismatch—that low grades result in attrition from the majors, and that African-American students’ GRE and MCAT scores were worse than whites who had entered college with similar credentials. This remarkably complete database, currently held in the HERI archives, would be ideal for testing mismatch effects on standardized post-college tests like the GRE and MCAT. Thus far, we have not been able to make arrangements to use the dataset.

One note: In the executive summary at the beginning, the authors state that “white students show larger proportionate losses from scientist-practitioner careers during college than do other racial/ethnic groups.” This is misleading; whites are less likely to be scientist-practitioners because they are much more likely to be scientist/professors or engineers.