Building Excellence in Scientific Teaching: How Important Is the Evidence for Evidence-Based Teaching when Training STEM TAs?

Evidence-based teaching practices (EBTP)-like inquiry-based learning, inclusive teaching, and active learning (AL)-have been shown to benefit all students, especially women, first-generation, and traditionally minoritized students in science fields. However, little research has focused on how best to train teaching assistants (TAs) to use EBTP or on which components of professional development are most important. We designed and experimentally manipulated a series of presemester workshops on AL, dividing subjects into two groups. The Activity group worked in teams to learn an AL technique with a workshop facilitator. These teams then modeled the activity, with their peers acting as students. In the Evidence group, facilitators modeled the activities with all TAs acting as students. We used a mixed-methods research design (specifically, concurrent triangulation) to interpret pre- and postworkshop and postsemester survey responses. We found that Evidence group participants reported greater knowledge of AL after the workshop than Activity group participants. Activity group participants, on the other hand, found all of the AL techniques more useful than Evidence group participants. These results suggest that actually modeling AL techniques made them more useful to TAs than simply experiencing the same techniques as students-even with the accompanying evidence. This outcome has broad implications for how we provide professional development sessions to TAs and potentially to faculty.

The CURE for Cultivating Fastidious Microbes.

Course-Based Undergraduate Research Experiences (CUREs) expand the scientific educational benefits of research to large groups of students in a course setting. As part of an ongoing effort to integrate CUREs into first-year biology labs, we developed a microbiology CURE (mCURE) that uses a modified dilution-to-extinction high throughput culturing protocol for isolating abundant yet fastidious aquatic bacterioplankton during one semester. Students learn common molecular biology techniques like nucleic acid extraction, PCR, and molecular characterization; read and evaluate scientific literature; and receive training in scientific communication through written and oral exercises that incorporate social media elements. In the first three semesters, the mCUREs achieved similar cultivability success as implementation of the protocol in a standard laboratory setting. Our modular framework facilitates customization of the curriculum for use in multiple settings and we provide classroom exercises, assignments, assessment tools, and examples of student output to assist with implementation.

Phylogenetic community structure of North American desert bats: influence of environment at multiple spatial and taxonomic scales.

Numerous processes influence community structure. The relative importance of these processes is thought to vary with spatial, temporal and taxonomic scales: density-dependent interactions are thought to be most important at small scales; at intermediate scales, environmental conditions may be the most influential factor; and biogeographic processes are thought to be of greater importance at larger scales. Additionally, the stress-dominance hypothesis suggests that communities experiencing harsher environmental conditions will be predominantly structured by habitat filtering, whereas communities experiencing more favourable conditions will be structured predominantly by density-dependent interactions such as competition. The aim of this study was to investigate the influence of environmental factors on phylogenetic community structure (PCS) of North American desert bats at multiple spatial and taxonomic scales. We also examined whether the stress-dominance hypothesis is upheld in desert bats across an environmental gradient. Phylogenetic community structure metrics were calculated using species pools that differed in spatial (from all deserts to individual deserts) and taxonomic (all bat taxa, a single family and a single genus) scales. We calculated mean temperature, precipitation and seasonality for each site to determine whether environmental gradients were related to degree of community structure. At the largest spatial and taxonomic scales, communities were significantly phylogenetically clustered while degree of clustering decreased at the smallest spatial and taxonomic scales. Climatic data, particularly mean temperature and temperature seasonality, were important predictors of PCS at larger scales and under harsher conditions, but at smaller scales and in less stressful conditions there was a weaker relationship between PCS and climate. This suggests that North American deserts, while harsh, are not uniform in the challenges they present to the faunas residing in them. Overall, the relationship between PCS and climatic data at large spatial and taxonomic scales, and in harsher conditions, suggests the influence of habitat filtering has been important in North American desert bat community assembly and that other processes have been important at smaller scales.