Optional Exam Retakes Reduce Anxiety but may Exacerbate Score Disparities Between Students with Different Social Identities.

Use of high-stakes exams in a course has been associated with gender, racial, and socioeconomic inequities. We investigated whether offering students the opportunity to retake an exam makes high-stakes exams more equitable. Following the control value theory of achievement emotions, we hypothesized that exam retakes would increase students' perceived control over their performance and decrease the value of a single exam attempt, thereby maximizing exam performance. We collected data on exam scores and experiences with retakes from three large introductory biology courses and assessed the effect of optional exam retakes on gender, racial/ethnic, and socioeconomic disparities in exam scores. We found that Black/African American students and those who worked more than 20 h a week were less likely to retake exams. While exam retakes significantly improved student scores, they slightly increased racial/ethnic and socioeconomic disparities in scores partly because of these differences in participation rates. Most students reported that retake opportunities reduced their anxiety on the initial exam attempt. Together our results suggest that optional exam retakes could be a useful tool to improve student performance and reduce anxiety associated with high-stakes exams. However, barriers to participation must be examined and reduced for retakes to reduce disparities in scores.

The Effects of Practice-Based Training on Graduate Teaching Assistants' Classroom Practices.

Evidence-based teaching is a highly complex skill, requiring repeated cycles of deliberate practice and feedback to master. Despite existing well-characterized frameworks for practice-based training in K-12 teacher education, the major principles of these frameworks have not yet been transferred to instructor development in higher educational contexts, including training of graduate teaching assistants (GTAs). We sought to determine whether a practice-based training program could help GTAs learn and use evidence-based teaching methods in their classrooms. We implemented a weekly training program for introductory biology GTAs that included structured drills of techniques selected to enhance student practice, logic development, and accountability and reduce apprehension. These elements were selected based on their previous characterization as dimensions of active learning. GTAs received regular performance feedback based on classroom observations. To quantify use of target techniques and levels of student participation, we collected and coded 160 h of video footage. We investigated the relationship between frequency of GTA implementation of target techniques and student exam scores; however, we observed no significant relationship. Although GTAs adopted and used many of the target techniques with high frequency, techniques that enforced student participation were not stably adopted, and their use was unresponsive to formal feedback. We also found that techniques discussed in training, but not practiced, were not used at quantifiable frequencies, further supporting the importance of practice-based training for influencing instructional practices.

Comparative sequence analysis of the SALT OVERLY SENSITIVE1 orthologous region in Thellungiella halophila and Arabidopsis thaliana.

To provide a framework for studies to understand the contribution of SALT OVERLY SENSITIVE1 (SOS1) to salt tolerance in Thellungiella halophila, we sequenced and annotated a 193-kb T. halophila BAC containing a putative SOS1 locus (ThSOS1) and compared the sequence to the orthologous 146-kb region of the genome of its salt-sensitive relative, Arabidopsis thaliana. Overall, the two sequences were colinear, but three major expansion/contraction regions in T. halophila were found to contain five Long Terminal Repeat retrotransposons, MuDR DNA transposons and intergenic sequences that contribute to the 47.8-kb size variation in this region of the genome. Twenty-seven genes were annotated in the T. halophila BAC including the putative ThSOS1 locus. ThSOS1 shares gene structure and sequence with A. thaliana SOS1 including 11 predicted transmembrane domains and a cyclic nucleotide-binding domain; however, different patterns of Simple Sequence Repeats were found within a 540-bp region upstream of SOS1 in the two species.