NACTA Journal • Volume 65 • Nov 2020 - Oct 2021 26 The Efect of Extended Student Hours The Efect of Extended Student Hours On Performance of Students in an On Performance of Students in an Interdisciplinary, Introductory Undergraduate Interdisciplinary, Introductory Undergraduate Ecology Course Ecology Course Adrian Treves 1 , Nicholas J. Balster 2 University of Wisconsin-Madison Madison WI Abstract Large-enrollment, undergraduate college courses often use plenary reviews before exams. Alternatives such as no review, trivia games, or practice exams have been evaluated. We present a before-and-after comparison of a novel intervention to improve exam performance in an interdisciplinary, introductory ecology course enrolling 150–220 non-majors. We evaluated summative exam performance of 397 participants and non-participants across 3 exams after some students reviewed in ‘extended student hours’ of sequential student-led meetings with the instructor for >20 minutes per group of <8 students, compared to those using practice exams only. Using a repeated measures, within-subject Hills-Armitage ANOVA and grouped comparisons to detect main, dose, order, and carry-over efects, we found that 4 of 7 treatment groups averaged 73–78% before intervention and improved 7–14% over practice exam participants, whereas the other 3 treatment groups that averaged 83–88% beforehand did not change after intervention, without signifcant order efects or carry-over efects. We found the positive, dose efect was 1<2=3. We present an approach to minimizing self-selection bias. It is unclear if the content or the format of extended student hours explained the efects. The efect size was similar to reports for trivia game reviews. Extended student hours appear to aid in formative assessment before exams. 1 Nelson Institute for Environmental Studies, 30A Science Hall, 550 North Park Street, University of Wisconsin, Madison WI 53706, USA, +1-608-890-450, atreves@wisc.edu 2 Department of Soil Science, 341 King Hall, 1475 Observatory Dr., University of Wisconsin, Madison WI 53706, USA, (608) 263-5719, njbalster@wisc.edu 3 Corresponding author: atreves@wisc.eduwisc.edu ORCID 0000-0002-3052-4708 4 Acknowledgments.. NSF provided support under S-STEM award #1643946 5 Human subjects protection: This study was deemed exempt by University of Wisconsin-Madison Institutional Review Board SDS/ER 2018-0264 under federal regulation 45 CFR 46.102(l). Introduction Exam review has been shown to improve exam performance compared to no review (King, 2010). A few methods of exam review have been subject to rigorous evaluation, including traditional (what we here call plenary review sessions in class), practice exam reviews, and trivia game reviews before exams, to name a few (Hackathorn et al., 2012). Yet, at the time of this writing, only 12 studies cite the latter study, so we echo their assertion that there remains a paucity of strong evidence supporting diferent methods of review to increase student exam performance. Dissatisfaction with traditional (plenary) exam reviews arose from students as well as instructors, although perceived efectiveness of exam reviews does not always match measured efectiveness (Hackathorn et al., 2012). Among the criticisms, many plenary reviews become didactic exchanges in lecture format, a modality shown to promote passive, superfcial learning (Chickering and Gamson, 1987; Penner, 1984). Moreover, review sessions tend to backfll information missed during regular classroom instruction and can vary from teacher-centered summaries to active learning exercises (e.g., problem-based). The more student-centered the exam reviews have been the more they show increases in durable learning, reduce test anxiety, and increase academic success for a variety of students (Felder, 2002; Garhenhire, 1996), while providing formative assessment for an instructor’s evaluation of content mastery (DiCarlo 2009; Qureshi et al., 2012). However, many studies are confounded by possible self- selection by already high-achieving students inclined to