Graduate teaching assistants (GTAs) play an integral role in undergraduate STEM education. Investment in training initiatives equips GTAs with evidence-based teaching strategies. This study investigates chemistry GTAs’ responses to a questioning strategy, known as Stretch-It, during a training program enhanced with rehearsal in a mixed reality teaching simulator. The GTAs’ use of Stretch-It questioning in the simulator was recorded over three training sessions (before, during, and after the strategy was introduced). Additionally, the GTAs’ use of Stretch-It questioning while teaching in an undergraduate general chemistry laboratory environment was investigated through in-class observations. The results support previous literature that training in a simulator environment can increase GTA proficiency in target skills while closely modeling a real-life teaching environment. Additionally, when using Stretch-It questioning in the classroom, GTAs used the strategy as an instructional and interactive technique during whole-group and individual interactions. Thus, tasking GTAs to practice Stretch-It questioning may be helpful for professional developers when promoting interactive teaching strategies.

The perceptions that physics mentors have about disability in physics influences how they interact with their mentees, and negative biases against disability can influence students to feel discouraged within the physics community. We administered the Disability and Physics Career Survey (DPCS) through physics-specific listservs and at physics-specific conferences to measure practicing physicists' knowledge about disability and their beliefs about the viability of physics careers for individuals with a variety of disability diagnoses. This study uses Cochran's Q and McNemar's R to compare how practicing physicists' perceptions of the viability for the careers of teacher and professor depend on the impairment that an individual is diagnosed with. We find that practicing physicists view these careers as non-viable for those with cognitive impairments and hold other unconscious biases that we outline and interrogate.

Background In college science laboratory and discussion sections, student-centered active learning strategies have been implemented to improve student learning outcomes and experiences. Research has shown that active learning activities can increase student anxiety if students fear that they could be negatively evaluated by their peers. Error framing (i.e., to frame errors as natural and beneficial to learning) is proposed in the literature as a pedagogical tool to reduce student anxiety. However, little research empirically explores how an instructor can operationalize error framing and how error framing is perceived by undergraduate students. To bridge the gap in the literature, we conducted a two-stage study that involved science graduate teaching assistants (GTAs) and undergraduate students. In stage one, we introduced cold calling (i.e., calling on non-volunteering students) and error framing to 12 chemistry and 11 physics GTAs. Cold calling can increase student participation but may increase student anxiety. Error framing has the potential to mitigate student anxiety when paired with cold calling. GTAs were then tasked to rehearse cold calling paired with error framing in a mixed-reality classroom simulator. We identified GTA statements that aligned with the definition of error framing. In stage two, we selected a few example GTA error framing statements and interviewed 13 undergraduate students about their perception of those statements. Results In the simulator, all the GTAs rehearsed cold calling multiple times while only a few GTAs made error framing statements. A thematic analysis of GTAs’ error framing statements identified ways of error indication (i.e., explicit and implicit) and framing (i.e., natural, beneficial, and positive acknowledgement). Undergraduate student interviews revealed specific framing and tone that are perceived as increasing or decreasing student comfort in participating in classroom discourse. Both undergraduate students and some GTAs expressed negative opinions toward responses that explicitly indicate student mistakes. Undergraduate students’ perspectives also suggest that error framing should be implemented differently depending on whether errors have already occurred. Conclusion Error framing is challenging for science GTAs to implement. GTAs’ operationalizations of error framing in the simulator and undergraduate students’ perceptions contribute to defining and operationalizing error framing for instructional practice. To increase undergraduate student comfort in science classroom discourse, GTAs can use implicit error indication. In response to students’ incorrect answers, GTAs can positively frame students’ specific ideas rather than discussing broadly how errors are natural or beneficial.

In interviews with physics students and early career physicists, we ask about their experiences with having impairments in the physics setting and physics culture.In this paper, we highlight how experiences shared by participants as disabled people in physics represent clusters of models of disability.Specifically, we apply a theoretical framing of a three-dimensional disability model space, with axes defined as medical versus social (i.e., cause); tragedy versus affirmative (i.e., effect); and minority group versus universal (i.e., ability/disability dichotomy).For example, in this framework, providing accommodations is described by a cluster of the social and minority models of disability.By analyzing participants' experiences in physics through this disability framework, we aim to identify the models that underpin supportive experiences and support the development of policies and professional development for the physics community towards benefiting disabled people.Through analysis and comparison of these models and participants' narratives, we offer a discussion and possible guidelines for instructors interacting with students with disabilities, opportunities for those with disabilities to deconstruct their own prior experiences and analyze potential misinterpretations that may arise from the models. .

Despite the positive gains towards student learning outcomes and engagement, active learning has been shown to potentially increase student anxiety due to a fear of negative evaluation.A pedagogical strategy proposed to mediate this issue is known as error framing; it asks instructors to encourage a perception of errors as being a natural part of the learning process.Previous work on this project investigated how graduate teaching assistants (GTAs) operationalized error framing during their training in a mixed-reality simulator but did not investigate their usage of it in their classrooms.This analysis characterizes the error framing statements made by GTAs during a set of classroom observations.We find that GTAs who employ error framing effectively avoid statements that might decrease student comfort and instead tend towards implicit, indirect strategies.

Students with disabilities involved in postsecondary physics education may benefit from research opportunities and mentorship.However, the literature documenting supports provided by physics mentors to disabled students is limited.In this study, we analyze interviews with five mentors who either instruct physics courses or lead a research group for examples of how they support disabled students doing research or seeking career advice.Furthermore, we contextualize the examples of supports using six models of disability.Models include the cause of disability (medical/social), the effect of impairment on well-being (tragedy/affirmative), and the dichotomy of dis/ability (minority/universal).We find mentors discuss supports provided to disabled students in research settings that align with clusters of models of disability.While there is not one set of models that yields a one-size-fits-all solution, the universal model plus social model cluster can help mentors design useful and durable supports.

Physics graduate teaching assistants (GTAs) are tasked with multifaceted teaching assignments, such as leading tutorials and inquiry-based laboratories, yet their professional development rarely includes opportunities to rehearse complex pedagogical skills or receive feedback on their teaching. In this study, physics GTAs practiced specific pedagogical skills during four sessions in a mixed-reality classroom simulator; here, we focus on GTAs' use of a specific questioning strategy called "Stretch-It." GTAs can apply Stretch-It by asking students to explain their logic (Explain Logic), either by explaining their work or providing evidence for their claim; or by asking students to take the content further (Follow-Up), either by applying it in an analogous situation or answering the initial question in another way. We found GTAs used all four types of Stretch-It subcategories during simulator sessions that incorporated facilitator feedback about their use of questioning. We also compared the use of Stretch-It questioning in the classroom for a pretraining semester cohort and the high-intensity simulator training cohort and found that the high intensity cohort's average use of Explain Logic questions in the observation immediately following the Stretch-It rehearsal was meaningfully higher than the pretraining cohort's average use of Explain Logic. However, the high-intensity cohort's use of Explain Logic is unstable, and values fall back within the pretraining average in subsequent classroom observations. We did not find a significant difference between the cohorts' use of Follow-Up. We discuss the implications of our findings for science, technology, engineering, and medicine GTA professional development and the significance of providing feedback to GTAs about their teaching.

There is an assumption that graduate teaching assistants (GTAs) have mastery of the chemistry content they are teaching and preparation to instruct students. However, in reformed classrooms, GTAs may need more support and resources. We designed chemistry rehearsal modules for use in a mixed-reality teaching simulator to help prepare GTAs for instruction in reformed classrooms by targeting pedagogical skills. The modules included familiar curricular activities and research-based student conceptions. We conducted an exploratory study with three experienced GTAs to investigate the utilization of the module inside the simulator. The three GTAs practiced cold calling and error framing and participated in a 1-h interview based on their experience. We recorded, transcribed, and coded the interviews and the simulator sessions. The three GTAs implemented the skills and provided feedback that supported the use of the module in the simulator and the authentic nature of the practice. Simulated environments that encourage personalized learning, skill practice, and responding to literature-based student ideas provide a promising avenue for graduate teaching assistant professional development.

In this study, we evaluate the impact of rehearsing teaching skills in a mixed-reality classroom simulator on graduate teaching assistants' (GTAs) instructional practices as well as undergraduate student learning outcomes. The simulator training is intended to provide GTAs opportunities to deliberately practice essential pedagogical skills that support active learning, specifically in the context of the combined tutorial and laboratory sections of an algebra-based introductory physics sequence. Over three semesters, GTAs participated in different numbers of simulator rehearsal sessions: no simulator training, one session, and four sessions. We conducted 109 classroom observations for 23 GTAs, using a modified version of the Laboratory Observation Protocol for Undergraduate STEM (LOPUS); we also documented the frequencies of questioning-related skills (e.g., cold calling) implemented by the GTAs. Undergraduate student learning outcomes were measured by pre- and posttests of the Force Concept Inventory (FCI) and Conceptual Survey of Electricity and Magnetism (CSEM). To classify and characterize GTAs' instructional practices, we conducted a hierarchical cluster analysis and found three instructional styles: the small-group facilitator, the whole-class facilitator, and the waiter. The results suggest that four-session simulator training throughout a semester supported GTAs (i) to shift away from the style of the waiter toward the whole-class facilitator, and (ii) to implement posing questions and cold calling techniques. While new GTAs were found to have more interactive behaviors than experienced GTAs in the semester with no simulator training, we found that four-session simulator training supported both new and experienced GTAs to use more interactive instructional styles and to implement questioning-related skills more frequently. Although the results demonstrate the effectiveness of simulator training, our analysis also indicates areas for improvement. GTAs tended to shift away from the style of the small-group facilitator toward the whole-class facilitator when they participated in four-session training, and the weekly implementations of questioning-related skills decreased over the course of a semester despite an increased total implementation. In addition, student learning outcomes in different semesters (with different numbers of simulator rehearsal sessions) did not show a statistically significant difference. However, GTAs' instructional styles were correlated with student performance on FCI posttest with a small effect size when controlling for FCI pretest scores and lecture instructors; no correlation was found between GTAs' instructional style and student performance on the CSEM posttest. We conclude with a discussion of factors that may have led to the success of the simulator training as well as strategies to further enhance the effectiveness of the simulator training.

We investigated student perceptions of cold calling on their feelings of anxiousness and how graduate teaching assistants (GTAs) alleviated these feelings when students shared their ideas publicly in the context of tutorial and laboratory sessions. Physics and chemistry GTAs who led active-learning tutorials and labs practiced cold calling paired with error framing with avatar-students in a mixed-reality simulator at the beginning of the semester. Then, we observed the GTAs teaching real students in their actual classroom. We recruited eleven students from sections led by GTAs who were observed to use cold calling in their classroom to participate in semi-structured interviews. Several students reported that cold calling increased their feelings of anxiousness. However, students also reported that GTAs used strategies paired with cold calling that reduced their feelings of anxiousness, such as acknowledging student responses as valuable and remembering student names. We discuss implications for professional development on active learning strategies.

Background Graduate teaching assistants (GTAs) often lead laboratory and tutorial sections in science, technology, engineering, and mathematics (STEM), especially at large, research-intensive universities. GTAs’ performance as instructors can impact student learning experience as well as learning outcomes. In this study, we observed 11 chemistry GTAs and 11 physics GTAs in a research-intensive institution in the southeastern USA. We observed the GTAs over two consecutive semesters in one academic year, resulting in a total of 58 chemistry lab observations and 72 physics combined tutorial and lab observations. We used a classroom observation protocol adapted from the Laboratory Observation Protocol for Undergraduate STEM (LOPUS) to document both GTA and student behaviors. We applied cluster analysis separately to the chemistry lab observations and to the physics combined tutorial and lab observations. The goals of this study are to classify and characterize GTAs’ instructional styles in reformed introductory laboratories and tutorials, to explore the relationship between GTA instructional style and student behavior, and to explore the relationship between GTA instructional style and the nature of laboratory activity. Results We identified three instructional styles among chemistry GTAs and three different instructional styles among physics GTAs. The characteristics of GTA instructional styles we identified in our samples are different from those previously identified in a study of a traditional general chemistry laboratory. In contrast to the findings in the same prior study, we found a relationship between GTAs’ instructional styles and student behaviors: when GTAs use more interactive instructional styles, students appear to be more engaged. In addition, our results suggest that the nature of laboratory activities may influence GTAs’ use of instructional styles and student behaviors. Furthermore, we found that new GTAs appear to behave more interactively than experienced GTAs. Conclusion GTAs use a variety of instructional styles when teaching in the reformed laboratories and tutorials. Also, compared to traditional laboratory and tutorial sections, reformed sections appear to allow for more interaction between the nature of lab activities, GTA instructional styles, and student behaviors. This implies that high-quality teaching in reformed laboratories and tutorials may improve student learning experiences substantially, which could then lead to increased learning outcomes. Therefore, effective GTA professional development is particularly critical in reformed instructional environments.

We investigated how changing the physical classroom impacted graduate teaching assistant (GTA) and student behaviors in tutorial sections of an introductory algebra-based physics sequence.Using a modified version of the Laboratory Observation Protocol for Undergraduate STEM (LOPUS), we conducted 35 observations over two semesters for seven GTAs who taught in different styles of classrooms (i.e., active learning classrooms and traditional classrooms).We found that both GTAs and students changed behaviors in response to a change from an active learning classroom to a traditional classroom.GTAs were found to be less interactive with student groups and to lecture at the whiteboard more frequently.Correspondingly, student behaviors changed as students asked fewer questions during one-on-one interactions.These findings suggest that the instructional capacity framework, which typically focuses on interactions between instructors, students and instructional materials, should also include interactions with the learning space.We suggest administrators and departments consider the impact of changing to a traditional classroom when implementing student-centered instruction and emphasize how to use classroom space in GTA professional development.

In this study, we characterized GTAs' teaching practices in algebra-based introductory physics "mini-studios," which combine student-centered recitation and inquiry-based labs. We documented both GTA and student actions using an observation protocol adapted from the Laboratory Observation Protocol for Undergraduate STEM (LOPUS). We observed 72 mini-studio sessions led by 11 GTAs over two semesters. We used an agglomerative hierarchical cluster analysis and identified three clusters that described the similarities and differences between individual sessions. Two clusters contained sessions characterized by more interactive GTAs but they varied in the amount of feedback, lecture and whole class questioning the GTA provided. In the third cluster, GTAs tended to wait for students to call on them before engaging. Student behaviors also varied between the clusters, suggesting correlations between student behaviors and GTA instructional styles, in contrast to previous findings with LOPUS in other contexts. We discuss implications of these findings for future research.

Recent research has highlighted the need to explore the propagation of innovative teaching strategies. SCALE-UP (StudentCentered Active Learning Environment with Upside-Down Pedagogies) is one such innovative strategy that requires transforming the learning space to support small group work. SCALE-UP is both well-propagated and frequently sustained within departments once it is implemented, possibly due to the investment in a transformed learning space. However, not all instructors and departments reach the significant learning gains typically documented in the literature. In this study, we use interviews to explore the extent to which individual instructors implement and sustain specific features of SCALE-UP, like reduced lecture time and group composition, because such features may be more easily modified over time than the classroom space. We report on instructors' perceptions of the extent to which their courses align with the SCALE-UP model and whether deviations from the literature-based model result from intentional or unintentional changes.

We show for high-symmetry disk, square, or equilateral triangular thin microstrip antennas of any composition respectively obeying C∞v, C4v, and C3v point group symmetries, that the transverse magnetic electromagnetic cavity mode wave functions are restricted in form to those that are one-dimensional representations of those point groups. Plots of the common nodal points of the ten lowest-energy non-radiating two-dimensional representations of each of these three symmetries are presented. For comparison with symmetry-broken disk intrinsic Josephson junction microstrip antennas constructed from the highly anisotropic layered superconductor Bi2Sr2CaCu2O8+δ (BSCCO), we present plots of the ten lowest frequency orthonormal wave functions and of their emission power angular distributions. These results are compared with previous results for square and equilateral triangular thin microstrip antennas.

We calculate the standing wave functions for pie-shaped wedge microstrip antennas of various wedge angles ϕ0. We then calculate the emission distributions from the uniform Josephson current and from the excitation of a cavity mode generated from the stand wave functions. For a narrow dieter's pie slice, quantitative fits to the experimental data on a Bi2Sr2CaCu2O8+δ narrow isosceles triangular mesa are shown.

Klemm, RA (reprint author), Show less Univ Cent Florida, Dept Phys, 4111 Libra Dr, Orlando, FL 32816 USA, richard.klemm@ucf.edu

The emission of coherent radiation from the intrinsic Josephson junctions in the high transition temperature Tc superconductor Bi2Sr2CaCu2O8+δ (Bi2212) arises from two sources: (1) the uniform part of the ac Josephson current satisfying the Josephson relation f = fJ = 2ev/h, where e is the electronic charge, v is the applied voltage per junction, and h is Planck's constant, and (2) when f = fc (n,m) matches that of the (n,m) the electromagnetic geometrical cavity mode of the thin device, the emission power can be greatly enhanced [1]. For conventional devices such as mesas carved from the top of a Bi2212 single crystal [2,4], the Bi2212 substrate not only absorbs much of the emission nearly parallel to the substrate [1], but its poor thermal conductivity leads to Joule heating,f Tc [5]. However, “thermally-managedstand-alone” devices constructed by removing the mesa from its Bi2212 substrate, covering its top and bottom surfaces with Au and sandwiching it between sapphire plates [3,6], narrow-linewidth emission at the world-record 2.4 THz from a superconductor was observed [7], placing a lower limit of ∆min ≥ 9.8meV on the bulk Bi2212 gap function, and filling the “THz gap” with a tunable, continuous-wave emitter. Moreover, the emission spectra from that high-symmetry disk [7] and unpublished high-symmetry square devices strongly suggest that only cavity modes obtained from wave functions that are one-dimensional representations of the appropriate point group can lead to electromagnetic cavity mode enhancements [3,7-9]. A theoretical explanation of this previously unknown restriction is presented. [1] R.A.Klemm and K.Kadowaki, J. Phys.: Condens. Matter 22, 375701 (2010). [2] M. Tsujimoto et al., Phys. Rev. Lett. 105, 037005 (2010). [3] M. Tsujimoto et al., Phys. Rev. Lett. 108, 107006 (2012). [4] K. Delfanazari et al., Opt. Express 21, 2171 (2013). [5] H. Minami et al., Phys. Rev. B 89, 054503 (2014). [6] T. Kashiwagi et al., Phys. Rev. Applied 4, 054018 (2015). [7] T. Kashiwagi et al., Appl. Phys. Lett.107, 082601 (2015). [8] D. P. Cerkoney et al., J. Phys.: Condens. Matter 29, 015601 (2017). [9] R. A. Klemm, A. E. Davis, and Q. X. Wang, IEEE J. Sel. Top. Quant. Electron.(2017, inpress) DOI 10.1109/JSTQE.2017.2649459