Assessing the quality of a student-generated question repository

We present results from a study that categorizes and assesses the quality of questions and explanations authored by students, in question repositories produced as part of the summative assessment in introductory physics courses over the past two years. Mapping question quality onto the levels in the cognitive domain of Bloom's taxonomy, we find that students produce questions of high quality. More than three-quarters of questions fall into categories beyond simple recall, in contrast to similar studies of student-authored content in different subject domains. Similarly, the quality of student-authored explanations for questions was also high, with approximately 60% of all explanations classified as being of high or outstanding quality. Overall, 75% of questions met combined quality criteria, which we hypothesize is due in part to the in-class scaffolding activities that we provided for students ahead of requiring them to author questions.Comment: 24 pages, 5 figure

Peer Instruction observed in the wild

\u27Flipped\u27 or \u27inverted classroom\u27 approaches have been shown to enhance the effectiveness of teaching contact time. We have adopted this pedagogy in our introductory physics classes, in which we teach a mixed cohort of around 300 major and non-major students at a large, research-intensive university. A crucial element of class activity is the Peer Instruction methodology, in which students discuss and defend their conceptions of topics, with levels of student understanding gauged using clicker questions. We have studied student behavior during these Peer Instruction sessions using \u27smart pen\u27 technology, which allows us to match audio-recorded student conversations and pen strokes with their clicker votes in an unobtrusive way. We find that the large majority of student conversations result in students settling on the correct answer to the post-discussion clicker questions, and that the success of these conversations does not depend on the technical fluency of the students\u27 vocabulary. The smart pen recordings also allow us to assess any problems or ambiguities in the clicker questions themselves, thus affording the opportunity for informed revision of pathological clicker questions. Over two iterations of the class we have successfully modified a number of clicker questions in light of this feedback and find them to have correspondingly increased learning gains. Thus, this authentically-situated \u27in the wild\u27 study of student behavior has benefits both in terms of increased theoretical understanding of the instructional approach and also in direct refinement of the classroom resources, i.e. more learning with less confusion

The Changes in Attitudes and Beliefs of First Year Physics Undergraduates: A Study Using the CLASS Survey

Personal attitudes and beliefs towards learning can influence the way students approach and study a subject; as a result, evaluation of attitudes and how these change over time is becoming increasingly common. We have carried out a study looking at the changes in attitudes of first year physics students over two years at the University of Edinburgh. The Colorado Learning Attitudes About Science Survey (CLASS) was used to obtain a measure of expert-like thinking for students both pre- and post- first year teaching. The results have been subdivided to look at the differences between physics `majors' and `non-majors' as well as the differences in attitudes of female and male students. It was found, in line with previous studies, that students' levels of expert-like thinking decline after initial instruction. When the data was subdivided to look in more detail at specific sections of the undergraduate class it was seen that the decrease in expert-like thinking is much more marked in `non-majors' - those students not intending to take physics as a degree - and also greater in female students than their male peers

Solitons in Five Dimensional Minimal Supergravity: Local Charge, Exotic Ergoregions, and Violations of the BPS Bound

We describe a number of striking features of a class of smooth solitons in gauged and ungauged minimal supergravity in five dimensions. The solitons are globally asymptotically flat or asymptotically AdS without any Kaluza-Klein directions but contain a minimal sphere formed when a cycle pinches off in the interior of the spacetime. The solutions carry a local magnetic charge and many have rather unusual ergosurfaces. Perhaps most strikingly, many of the solitons have more electric charge or, in the asymptotically AdS case, more electric charge and angular momentum than is allowed by the usual BPS bound. We comment on, but do not resolve, the new puzzle this raises for AdS/CFT.Comment: 60 pages, 12 figures, 3 table

De novo designed peptide and protein hairpins self‐assemble into sheets and nanoparticles

AFM, TEM, fluorescence microscopy image files and spectral data published in DOI:10.1002/smll.202100472. Preprint of this is available at bioRxiv DOI:10.1101/2020.08.14.25146

Pathologies in Asymptotically Lifshitz Spacetimes

There has been significant interest in the last several years in studying possible gravitational duals, known as Lifshitz spacetimes, to anisotropically scaling field theories by adding matter to distort the asymptotics of an AdS spacetime. We point out that putative ground state for the most heavily studied example of such a spacetime, that with a flat spatial section, suffers from a naked singularity and further point out this singularity is not resolvable by any known stringy effect. We review the reasons one might worry that asymptotically Lifshitz spacetimes are unstable and employ the initial data problem to study the stability of such systems. Rather surprisingly this question, and even the initial value problem itself, for these spacetimes turns out to generically not be well-posed. A generic normalizable state will evolve in such a way to violate Lifshitz asymptotics in finite time. Conversely, enforcing the desired asymptotics at all times puts strong restrictions not just on the metric and fields in the asymptotic region but in the deep interior as well. Generically, even perturbations of the matter field of compact support are not compatible with the desired asymptotics.Comment: 36 pages, 1 figure, v2: Enhanced discussion of singularity, including relationship to Gubser's conjecture and singularity in RG flow solution, plus minor clarification

Pre-cooling for endurance exercise performance in the heat: a systematic review.

PMCID: PMC3568721The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1741-7015/10/166. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Endurance exercise capacity diminishes under hot environmental conditions. Time to exhaustion can be increased by lowering body temperature prior to exercise (pre-cooling). This systematic literature review synthesizes the current findings of the effects of pre-cooling on endurance exercise performance, providing guidance for clinical practice and further research

Analyzing learning during Peer Instruction dialogues:A resource activation framework

Peer Instruction (PI) is an evidence based pedagogy commonly used in undergraduate physics instruction. When asked questions designed to test conceptual understanding, it has been observed that the proportion of students choosing the correct answer increases following peer discussion; however, relatively little is known about what takes place during these discussions or how they are beneficial to the processes of learning physics [M. C. James and S. Willoughby, Am. J. Phys. 79, 123 (2011)]. In this paper a framework for analyzing PI discussions developed through the lens of the “resources model” [D. Hammer, Am. J. Phys. 64, 1316 (1996); D. Hammer et al., Information Age Publishing (2005)] is proposed. A central hypothesis for this framework is that the dialogue with peers plays a crucial role in activating appropriate cognitive resources, enabling the students to see the problem differently, and therefore to answer the questions correctly. This framework is used to gain greater insights into the PI discussions of first year undergraduate physics students at the University of Edinburgh, UK, which were recorded using Livescribe Smartpens. Analysis of the dialogues revealed three different types of resource activation corresponding to increasing cognitive grain size. These were activation of knowledge elements, activation of linkages between knowledge elements, and activation of control structures (epistemic games and epistemological frames). Three case studies are examined to illustrate the role that peer dialogue plays in the activation of these cognitive resources in a PI session. The implications for pedagogical practice are discussed