Closed or Open Book for Invigilated Tests – Does It Make a Difference?

COVID-19 has had many impacts on economics education including assessment. One such impact has been the shift to more open book rather than closed book testing in order to retain flexibility to shift online at short notice. In this study, I compare the scores of students in a first year macroeconomics course at a New Zealand university from two different years. Both groups of students answered identical multiple-choice questions (that neither group of students had seen before) where the only difference in the assessment was closed vs open book. I compare both test formats at the total level and then compare scores across the two formats with questions grouped according to Bloom’s taxonomy. I examine the difference in scores of groups of students, viz.: (1) gender; (2) international vs domestic; and (3) GPA grouping. Among other results, I find that students score better in open book tests in lower Bloom’s taxonomy level questions but worse in higher. However, this effect does differ across different types of students, notably when comparing females and males and students with a higher or lower overall GPA.