Effect size measures are a key complement to statistical significance testing when reporting quantitative research findings. The authors provide a rationale for use of effect size and specific tools and guidelines for interpretation of results.

The authors investigated the extent to which postdoctoral fellows believed in and implemented evidence-based pedagogies after completion of a 2-yr professional development program, FIRST IV. Postdocs reported greater use of learner-centered compared with teacher-centered instruction, and video ratings further documented learner-centered instruction.

Amphibian tadpoles display extensive anti-predator phenotypic plasticity, reducing locomotory activity and, with chronic predator exposure, developing relatively smaller trunks and larger tails. In many vertebrates, predator exposure alters activity of the neuroendocrine stress axis. We investigated predator-induced effects on stress hormone production and the mechanistic link to anti-predator defences in Rana sylvatica tadpoles. Whole-body corticosterone (CORT) content was positively correlated with predator biomass in natural ponds. Exposure to caged predators in mesocosms caused a reduction in CORT by 4 hours, but increased CORT after 4 days. Tadpoles chronically exposed to exogenous CORT developed larger tails relative to their trunks, matching morphological changes induced by predator chemical cue; this predator effect was blocked by the corticosteroid biosynthesis inhibitor metyrapone. Tadpole tail explants treated in vitro with CORT increased tissue weight, suggesting that CORT acts directly on the tail. Short-term treatment of tadpoles with CORT increased predation mortality, likely due to increased locomotory activity. However, long-term CORT treatment enhanced survivorship, likely due to induced morphology. Our findings support the hypothesis that tadpole physiological and behavioural/morphological responses to predation are causally interrelated. Tadpoles initially suppress CORT and behaviour to avoid capture, but increase CORT with longer exposure, inducing adaptive phenotypic changes.

We tested the effectiveness of Faculty Institutes for Reforming Science Teaching IV (FIRST), a professional development program for postdoctoral scholars, by conducting a study of program alumni. Faculty professional development programs are critical components of efforts to improve teaching and learning in the STEM (Science, Technology, Engineering, and Mathematics) disciplines, but reliable evidence of the sustained impacts of these programs is lacking. We used a paired design in which we matched a FIRST alumnus employed in a tenure-track position with a non-FIRST faculty member at the same institution. The members of a pair taught courses that were of similar size and level. To determine whether teaching practices of FIRST participants were more learner-centered than those of non-FIRST faculty, we compared faculty perceptions of their teaching strategies, perceptions of environmental factors that influence teaching, and actual teaching practice. Non-FIRST and FIRST faculty reported similar perceptions of their teaching strategies and teaching environment. FIRST faculty reported using active learning and interactive engagement in lecture sessions more frequently compared with non-FIRST faculty. Ratings from external reviewers also documented that FIRST faculty taught class sessions that were learner-centered, contrasting with the teacher-centered class sessions of most non-FIRST faculty. Despite marked differences in teaching practice, FIRST and non-FIRST participants used assessments that targeted lowerlevel cognitive skills. Our study demonstrated the effectiveness of the FIRST program and the empirical utility of comparison groups, where groups are well matched and controlled for contextual variables (for example, departments), for evaluating the effectiveness of professional development for subsequent teaching practices.

The goal of STEM professional development for teaching is that participants continue to practice what they learn in the long term. However, we do not know if the outcomes are achieved and ultimately persist. We tracked postdoctoral participants from the Faculty Institutes for Reforming Science Teaching (FIRST) IV program into their current positions as early-career biology faculty. We assessed their teaching approaches, practices, and student perceptions of the learning environment over 6 to 9 years after finishing the program. Simultaneously, we evaluated paired faculty in the same departments. We found that professional development outcomes persisted over time and across a career transition. FIRST IV faculty maintained their learner-centered practices and were more learner-centered than their peers. Last, we found that teaching approaches were correlated with teaching practices in all faculty participants. These results provide evidence for the success of the FIRST IV program and the long-term persistence of professional development outcomes.