From: Evolution and Medicine: An Inquiry-Based High School Curriculum Supplement
 | Pretest mean number correct | Posttest mean number correct | t test | Cohen’s d effect size (lower, upper 95% confidence intervals) |
---|---|---|---|---|
Complete test (10 items) | 4.47 | 5.69 | p < .001 | 0.7 (.58, .80) |
Common ancestry only (5 items) | 1.66 | 2.63 | p < .001 | 0.8 (.70, .92) |
Natural selection only (5 items) | 2.81 | 3.04 | p < .001 | 0.2 (.10, .31) |