Using Entering Student Data to Estimate Campus Retention Rates

1. Using Entering Student Data to Estimate Campus Retention Rates LINDA J. SAX Associate Professor & Associate Director of HERI University of California, Los Angeles May 31, 2005

2. Student-Right-To-Know Act As of 1993, four-year institutions are compared on a six-year retention rate • Ignores: • Stop-outs • Transfers • Differences between institutions (missions, resources) • Student background characteristics • Account for 2/3 variation in institutional degree completion rates

3. 2000 HERI Retention Study • 262 baccalaureate institutions • 56,818 students • 1994 CIRP Freshman Survey • 2000 Registrar’s Survey collected 4- and 6-year degree attainment data

4. Both retention measures (4-year and 6-year) highly dependent on student background characteristics • Strongest effects: • High school grades • SAT score • Gender • Race

7. How can we estimate an institution’s retention rate if we know the gender, high school grades and SAT scores of a college’s entering freshman class?

8. Computing an Expected Retention Rate 1. Compute for each student an expected probability of retention (Y-hat) Formula 1: Y-hat = a + b1(HSGPA) Formula 2: Y-hat = a + b1(HSGPA) + b2(SAT) Formula 3: Y-hat = a + b1(HSGPA) + b2(SAT) + b3(Sex) 2. Compute mean Y-hat across all students

9. Institutional Effect = Actual Expected Retention - Retention Rate Rate

10. Major Historically Research Black University College Actual Retention = 35 36 Rate

11. Major Historically Research Black University College Actual Rate = 35 36 Expected Rate = 64 22 “Effect” = -29 +14

12. 4-year Degree Attainment: Formula 1 Retention measure: Bachelor’s completion in 4 years Input data considered: High school GPA Expected retention rate = .0947 (GPA) - .1972 (HSGPA: A or A+ = 8; A- = 7; B+ = 6; B = 5; B- = 4; C+ = 3; C or C- = 2; D or less = 1) Examples: If A- average (GPA=7), probability = 47% If C+ average (GPA=2), probability = 9%

13. 4-year Degree Attainment: Formula 2 Retention Measure: Bachelor’s completion in 4 years Input data considered: High school GPA, SAT Expected retention rate = .0670 (GPA) + .000522 (SAT) - .5633 Examples: If A- average and 1300 SAT: Probability = 58% If C+ average and 900 SAT: Probability = 11%

14. 4-year Degree Attainment: Formula 3 Retention Measure: Bachelor’s completion in 4 years Input data considered: High school GPA, SAT, Sex Expected retention rate =.0615 (GPA) + .000569 (SAT) + .0717 (Sex: Female) - .6879 Examples: If female B student with 1200 SAT: Probability = 45% If male B student with 1200 SAT: Probability = 37%

15. Dozens of CIRP Variables Predict Retention, including: • Parental income and educational level (+) • Financial aid and student loans (+) • Working for pay, working off campus (expectations) (-) • Propensity towards academic engagement (+) • Propensity towards extracurricular involvement (+)

16. Overall Retention Rate: 50% Overall Prediction Using Formula 1: 37% (difference of –13%) Overall Prediction Using CIRP Variables: 44% (difference of –06%) Using CIRP Variables Greatly Improves the Accuracy of the Prediction