Preparing Biology Graduate Teaching Assistants for Their Roles as Instructors: An Assessment of Institutional Approaches.
ABSTRACT: The inconsistency of professional development (PD) in teaching for graduate teaching assistants (GTAs) is a widespread problem in higher education. Although GTAs serve an important role in retention of undergraduate science majors and in promotion of scientific literacy in nonmajors, they often lack preparation and ongoing support for teaching. Given the recent national focus on instructional quality in introductory courses, our goal was to use an online survey to identify current practices of teaching PD for biology GTAs and compare these results with the last national survey on this topic. In responses from 71 participant institutions, 96% reported some mandatory teaching preparation for biology GTAs; however, 52% of these programs required 10 or fewer hours per year. Respondents wanted to change their programs to include more pedagogical information and teaching observations with feedback to their GTAs. Programmatic self-ratings of satisfaction with GTA PD were positively correlated with the number of topics discussed during PD. Although more schools are requiring GTA PD for teaching compared with the last national survey, the lack of program breadth at many schools warrants a national conversation with regard to recent calls for improving undergraduate instruction.
Project description:Graduate teaching assistants (GTAs) in science, technology, engineering, and mathematics (STEM) have a large impact on undergraduate instruction but are often poorly prepared to teach. Teaching self-efficacy, an instructor's belief in his or her ability to teach specific student populations a specific subject, is an important predictor of teaching skill and student achievement. A model of sources of teaching self-efficacy is developed from the GTA literature. This model indicates that teaching experience, departmental teaching climate (including peer and supervisor relationships), and GTA professional development (PD) can act as sources of teaching self-efficacy. The model is pilot tested with 128 GTAs from nine different STEM departments at a midsized research university. Structural equation modeling reveals that K-12 teaching experience, hours and perceived quality of GTA PD, and perception of the departmental facilitating environment are significant factors that explain 32% of the variance in the teaching self-efficacy of STEM GTAs. This model highlights the important contributions of the departmental environment and GTA PD in the development of teaching self-efficacy for STEM GTAs.
Project description:Graduate teaching assistants (GTAs) play important instructional roles in introductory science courses, yet they often have little training in pedagogy. The most common form of teaching professional development (PD) for GTAs is a presemester workshop held at the course, department, or college level. In this study, we compare the effectiveness of presemester workshops at three northeastern research universities, each of which incorporated scientific teaching as the pedagogical content framework. The comparison of GTA PD program outcomes at three different institutions is intended to test theoretical assertions about the key role of contextual factors in GTA PD efficacy. Pretest and posttest surveys were used to assess changes in GTA teaching self-efficacy and anxiety following the workshops, and an objective test was used to assess pedagogical knowledge. Analysis of pretest/posttest data revealed statistically significant gains in GTA teaching self-efficacy and pedagogical knowledge and reductions in teaching anxiety across sites. Changes in teaching anxiety and self-efficacy, but not pedagogical knowledge, differed by training program. Student ratings of GTAs at two sites showed that students had positive perceptions of GTAs in all teaching dimensions, and relatively small differences in student ratings of GTAs were observed between institutions. Divergent findings for some outcome variables suggest that program efficacy was influenced as hypothesized by contextual factors such as GTA teaching experience.
Project description:There has been little attention given to teaching beliefs of graduate teaching assistants (GTAs), even though they represent the primary teaching workforce for undergraduate students in discussion and laboratory sections at many research universities. Secondary school education studies have shown that teaching beliefs are malleable and can be shaped by professional development, particularly for inexperienced teachers. This study characterized inexperienced GTAs' teaching beliefs about student learning and how they change with a science-specific pedagogy course that emphasized student learning. GTA teaching beliefs were characterized as traditional (providing information to students), instructive (providing activities for students), and transitional (focusing on student-teacher relationships). At the start of the course, traditional, instructive, and transitional beliefs were emphasized comparably in the concept maps and presentations of inexperienced GTAs. At the end of the course, although GTAs' beliefs remained mostly teacher focused, they were more instructive than traditional or transitional. GTAs included teaching strategies and jargon from the course in their concept maps but provided minimal explanations about how opportunities for active student engagement would impact student learning. These results suggest there is a need to provide ongoing discipline-specific professional development to inexperienced GTAs as they develop and strengthen their teaching beliefs about student learning.
Project description:OBJECTIVE:To determine the cost-effectiveness of Gynaecology Teaching Associate (GTA) teaching versus conventional pelvic model (manikin) teaching of pelvic examination skills for final year medical students within a UK undergraduate obstetrics and gynaecology (O&G) curriculum. METHODS:An economic evaluation was carried out alongside a randomised controlled trial involving 492 final year medical students. 240 students received manikin teaching, and 241 GTA-led teaching. 418 (85%) students completed their assessment. Proficiency in gynaecological pelvic examination on GTAs was estimated by a senior clinical examiner, blinded to the method of teaching, using a standardised assessment tool. University of Birmingham Medical School thresholds were applied to determine proficiency levels; competence (pass) 50%, merit 60% and distinction 70%. Costs incurred in the delivery of both the educational pathways (control and intervention) were combined. All costs are reported in 2013-2014 prices and earlier costs adjusted using inflation indices. OUTCOME MEASURES:Cost per student competent in pelvic examination at completion of a 5-week clinical O&G placement. RESULTS:GTA teaching was more effective compared with conventional teaching with 12 more students considered competent at pass level and 28 more students competent at merit and distinction levels, respectively. However, the average cost of GTA teaching was £45.06 per student compared with £7.40 per student for conventional teaching, with an increased cost of £37.66 per student. The incremental cost-effectiveness ratio demonstrated that it cost an additional £640.20 per competent student and £274.37 per student competent at merit level and £274.37 at distinction level compared with conventional manikin-based teaching. CONCLUSIONS:GTA teaching of female pelvic examination at the start of undergraduate medical student O&G clinical placements is shown to cost more and be more effective. GTA teaching is likely to be considered cost-effective in the context of other tests, and over the lifespan of a competent doctor's career. TRIAL REGISTRATION NUMBER:NCT01944592.
Project description: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.
Project description:Gene transfer agents (GTAs) are virus-like elements integrated into bacterial genomes, particularly, those of <i>Alphaproteobacteria</i> The GTAs can be induced under conditions of nutritional stress, incorporate random fragments of bacterial DNA into miniphage particles, lyse the host cells, and infect neighboring bacteria, thus enhancing horizontal gene transfer. We show that GTA genes evolve under conditions of pronounced positive selection for the reduction of the energy cost of protein production as shown by comparison of the amino acid compositions with those of both homologous viral genes and host genes. The energy saving in GTA genes is comparable to or even more pronounced than that in the genes encoding the most abundant, essential bacterial proteins. In cases in which viruses acquire genes from GTAs, the bias in amino acid composition disappears in the course of evolution, showing that reduction of the energy cost of protein production is an important factor of evolution of GTAs but not bacterial viruses. These findings strongly suggest that GTAs represent bacterial adaptations rather than selfish, virus-like elements. Because GTA production kills the host cell and does not propagate the GTA genome, it appears likely that the GTAs are retained in the course of evolution via kin or group selection. Therefore, we hypothesize that GTAs facilitate the survival of bacterial populations under energy-limiting conditions through the spread of metabolic and transport capabilities via horizontal gene transfer and increases in nutrient availability resulting from the altruistic suicide of GTA-producing cells.<b>IMPORTANCE</b> Kin selection and group selection remain controversial topics in evolutionary biology. We argue that these types of selection are likely to operate in bacterial populations by showing that bacterial gene transfer agents (GTAs), but not related viruses, evolve under conditions of positive selection for the reduction of the energy cost of GTA particle production. We hypothesize that GTAs are dedicated devices mediating the survival of bacteria under conditions of nutrient limitation. The benefits conferred by GTAs under nutritional stress conditions appear to include horizontal dissemination of genes that could provide bacteria with enhanced capabilities for nutrient utilization and increases of nutrient availability occurring through the lysis of GTA-producing bacteria.
Project description:Pharmacogenetic tests allow medications to be tailored to individual patients to improve efficacy and reduce drug toxicity. In 2005, the International Society of Pharmacogenomics (ISP) made recommendations for undergraduate medical teaching in pharmacogenetics. We aimed to establish the quantity and scope of this in British medical schools. An electronic survey was sent to all British medical schools. Nineteen out of 34 (56%) medical schools responded. Sixteen of the 19 (84%) respondents provided pharmacogenetics teaching, usually 1-2 h in total. Only four (21%) medical schools offered the four or more hours of teaching recommended by the ISP. However, 10 of 16 (63%) schools felt the amount of pharmacogenetic teaching offered was sufficient. The quantity of undergraduate teaching of pharmacogenetics is low. However, a majority of UK medical schools teach it, covering a broad scope of elements. It is encouraging that future clinicians are being provided with the knowledge to deliver pharmacogenetics into clinical practice.
Project description:Gene transfer agents (GTAs) are thought to be ancient bacteriophages that have been co-opted into serving their host and can now transfer any gene between bacteria. Production of GTAs is controlled by several global regulators through unclear mechanisms. In Rhodobacter capsulatus, gene rcc01865 encodes a putative regulatory protein that is essential for GTA production. Here, I show that rcc01865 (hereafter gafA) encodes a transcriptional regulator that binds to the GTA promoter to initiate production of structural and DNA packaging components. Expression of gafA is in turn controlled by the pleiotropic regulator protein CtrA and the quorum-sensing regulator GtaR. GafA and CtrA work together to promote GTA maturation and eventual release through cell lysis. Identification of GafA as a direct GTA regulator allows the first integrated regulatory model to be proposed and paves the way for discovery of GTAs in other species that possess gafA homologues.
Project description:Genetic exchange mediated by viruses of bacteria (bacteriophages) is the primary driver of rapid bacterial evolution. The priority of viruses is usually to propagate themselves. Most bacteriophages use the small terminase protein to identify their own genome and direct its inclusion into phage capsids. Gene transfer agents (GTAs) are descended from bacteriophages, but they instead package fragments of the entire bacterial genome without preference for their own genes. GTAs do not selectively target specific DNA, and no GTA small terminases are known. Here, we identified the small terminase from the model Rhodobacter capsulatus GTA, which then allowed prediction of analogues in other species. We examined the role of the small terminase in GTA production and propose a structural basis for random DNA packaging.IMPORTANCE Random transfer of any and all genes between bacteria could be influential in the spread of virulence or antimicrobial resistance genes. Discovery of the true prevalence of GTAs in sequenced genomes is hampered by their apparent similarity to bacteriophages. Our data allowed the prediction of small terminases in diverse GTA producer species, and defining the characteristics of a "GTA-type" terminase could be an important step toward novel GTA identification. Importantly, the GTA small terminase shares many features with its phage counterpart. We propose that the GTA terminase complex could become a streamlined model system to answer fundamental questions about double-stranded DNA (dsDNA) packaging by viruses that have not been forthcoming to date.
Project description:We present the Homeostasis Concept Inventory (HCI), a 20-item multiple-choice instrument that assesses how well undergraduates understand this critical physiological concept. We used an iterative process to develop a set of questions based on elements in the Homeostasis Concept Framework. This process involved faculty experts and undergraduate students from associate's colleges, primarily undergraduate institutions, regional and research-intensive universities, and professional schools. Statistical results provided strong evidence for the validity and reliability of the HCI. We found that graduate students performed better than undergraduates, biology majors performed better than nonmajors, and students performed better after receiving instruction about homeostasis. We used differential item analysis to assess whether students from different genders, races/ethnicities, and English language status performed differently on individual items of the HCI. We found no evidence of differential item functioning, suggesting that the items do not incorporate cultural or gender biases that would impact students' performance on the test. Instructors can use the HCI to guide their teaching and student learning of homeostasis, a core concept of physiology.