(Guest post by Larry Bernstein)
Yesterday, the College Board released a study of the predicative power of the SAT to estimate a student’s college freshman year grade point average. A Bloomberg article condemned the results because of the relative ineffectiveness of the new SAT to predict college grades. The predictive power of the SAT is trivially improved by the addition of the new essay exam which adds test time and is costly to grade.
I think this should come as no surprise, and it shows the general limitations of using standardized tests to predict college grades. One of the key points made in the study is that high school grades are a better predictor versus the SAT. High school grades need to be included with the SAT to best estimate GPA.
In my 1985 Wharton undergraduate statistics class, each student was required to create a regression research project. By chance, I chose to research predicting my classmate’s college GPA. I used 20 variables, including the SAT score, and I found only 5 variables with statistical significance: SAT score, number of hours studied, Jewish or Gentile, Wharton or other school such as the college of arts and sciences, and raised in the Northeast or elsewhere.
Similar to the national studies, in my survey of 100 fraternity brothers the SAT score did a mediocre job of predicting college GPA as a single variable. The key variable in my study was the number of hours studied. You would be surprised by the variance in Ivy Leaguers’ study habits. My survey asked students to estimate the number of hours as 1-10, 10-20, 20-30, or 30-40. My favorite response was: “Is this per semester?” I assumed the student would realize it was per week! Work habits and effort played a critical role in estimating college GPA. Obviously, the college placement office will have difficulty estimating this variable, though difficulty of course load and number of AP classes might help.
The rest of the variables seem obvious. It is much more difficult to get into Wharton than the other programs at Penn. So it is no surprise that Wharton students were running circles around the non-Wharton students, even adjusting for SAT scores and hours studied. In addition, it is much more difficult to get into Penn from the NE than from other areas of the country.
Very few of the Jews were jocks. Needless to say my college fraternity had plenty of sample problems.