1. 1 2008 AP Biology College Comparability Study

2. 2 What is a Comparability Study? AP college comparability studies are conducted periodically. An AP Biology study was conducted in 2007-2008. During a college comparability study, a portion of an AP Exam is administered to college students. The results of a college comparability study are considered when setting AP grades. The study ensures that AP standards are comparable to or higher than the grading standards that are applied by college instructors when evaluating the performance of their own students in corresponding college courses.

3. 3 AP Biology College Comparability Study Exam Format Two exams  Molecular/Cellular  Organismal/Ecological Each exam consists of:  25 multiple-choice questions  1 free-response question All items from previously administered exam

4. 4 AP Biology College Comparability Study Sample Size 19 colleges/universities 890 exam booklets  640 Molecular/Cellular  250 Organismal/Ecological

5. 5 AP Biology College Comparability Study Participating Institutions Ball State University Penn State University Boston University Rutgers University–Camden California Polytechnic State University Temple University Case Western Reserve University The College of New Jersey Davidson College The George Washington University Florida International University The University of North Carolina at Chapel Hill Indiana University–Purdue University University of Colorado at Boulder Loyola University Chicago University of Houston University of the Pacific Oklahoma State University Whitman College

6. 6 College Comparability Study Administration Procedures Instructors at each participating institution:  Administer the exam  Assign exam grades using their own standards  Report course and exam grades  Complete instructor’s questionnaire student background motivation of students weight given to exam alignment of exam content to college course taught

7. 7 College Comparability Study Scoring Procedures Grades submitted by instructors  Exam grade  Projected course grade Essay scores assigned by AP Readers with rubrics established during original reading Exams assigned composite scores to compare to original AP population

8. 8 College Comparability Study Grade Setting Process Equate college scores to same scale as full AP exam Calculate average college scores by exam grade for each college (ignore all F’s) The minimum exam score for each AP grade is compared to the average exam score of college students earning corresponding letter grade Find equivalent scores for 2008 test population

9. 9 Comparison of AP Students and College Students Mean Multiple Choice Mean Free Response Mean Composite AP students 452267 College students 501867

10. 10 AP Biology College Comparability Study Results (150-point scale) CollegesAP Students Exam Grade Average Score AP Grade Minimum Composite Score Average Score A96595108 B8247785 C6935968 D5623748 FN/A*1024 * Cases of college students to whom professors assigned an F for either the exam or the course were removed from the analysis.

11. 11 Factors that Affect the Location of Grade Boundaries Equating Comparability study data Judgment of Chief Reader

12. 12 AP Biology: Percentage of Students Earning Each AP Grade AP Grade20072008 519.3%18.3% 420.3%15.7% 321.2%16.1% 223.2%15.3% 115.9%34.6%

13. 13 Effect of Comp Study on Distribution 2008 Grade Distribution AP Grade Estimated by Equating Alone* Adjusted for the Comparability Study Data* 518.3% 421.7%15.7% 321.6%16.1% 222.1%15.3% 116.3%34.6% * >95% of the scores available