Quiz 3 Discussion


The unadjusted scores for test #3 pose a dilemma. The percentage of As is higher than the previous test, but Ds and Fs are at the highest levels for any test. Forty-two percent of the class received either a D or an F versus 27 percent on both prior tests.



What went wrong? It is possible that people choose to study less because the test was open-book, open-note, and therefore were less prepared going into the test. But students whose averages on tests #1 and #2 were As and Bs on prior tests scored on average 12 points lower on this test. Those who had averaged Cs on prior tests scored 10 points lower. By contrast, those who had Ds posted a 7-point average gain, and those who failed prior tests posted a 23-point average gain. In other words, students who scored well on prior tests did worse on this test, and students who scored worse on prior test did better on this test. These results are consistent with correlations between test scores: the correlation between test 1 and test 2 was .55  (with 0 being no connection and 1 being a perfect correlation). The T1-T3 and T2-T3 correlations were .17 and .28, respectively.