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The ground-breaking image of a black hole's event horizon, which captured the public's attention and imagination in April 2019, was captured using the power of interferometry: many separate telescopes working together to observe the cosmos in incredible detail. Many recent astrophysical discoveries that have revolutionized the scientific community's understanding of the cosmos were made by interferometers such as LIGO, ALMA, and the Event Horizon Telescope. Astro 101 instructors who want their students to learn the science behind these discoveries must teach about interferometry. Decades of research show that using active learning strategies can significantly increase students' learning and reduce achievement gaps between different demographic groups over what is achieved from traditional lecture-based instruction. As part of an effort to create active learning materials on interferometry, we developed and tested a new "Lecture-Tutorial" to help Astro 101 students learn about key properties of astronomical interferometers. This paper describes this new "Lecture-Tutorial" and presents evidence for its effectiveness from a study conducted with 266 Astro 101 students at the University of North Carolina at Chapel Hill.

In this paper we put forth a model for physics course reform that uniquely uses proven, research-based active-learning strategies to help students improve their physics knowledge and problem-solving skills. In this study, we compared the exam performance of students in two sections of the same introductory physics course. One section (the traditional section, N = 258) was taught by an instructor who is highly regarded for his lectures, but did not use any active-learning teaching strategies. The other section (the reformed section, N = 217) was taught by an instructor who had never before taught a physics class, but who was trained in physics and astronomy education research and who used active-learning teaching strategies. Students in the reformed section significantly outperformed students in the traditional section on common exam questions over the course of the semester, regardless of whether the question was conceptual or quantitative. This reform effort has been successful at improving students' learning and significantly increasing the department's use of active-learning strategies at the introductory level and beyond.

[This paper is part of the Focused Collection on Astronomy Education Research.] This paper presents the first item response theory (IRT) analysis of the national data set on introductory, general education, college-level astronomy teaching using the Light and Spectroscopy Concept Inventory (LSCI). We used the difference between students' pre- and postinstruction IRT-estimated abilities as a measure of learning gain. This analysis provides deeper insights than prior publications both into the LSCI as an instrument and into the effectiveness of teaching and learning in introductory astronomy courses. Our IRT analysis supports the classical test theory findings of prior studies using the LSCI with this population. In particular, we found that students in classes that used active learning strategies at least 25% of the time had average IRT-estimated learning gains that were approximately 1 logit larger than students in classes that spent less time on active learning strategies. We also found that instructors who want their classes to achieve an improvement in abilities of average [Delta Theta] = 1 logit must spend at least 25% of class time on active learning strategies. However, our analysis also powerfully illustrates the lack of insight into student learning that is revealed by looking at a single measure of learning gain, such as average [Delta Theta]. Educators and researchers should also examine the distributions of students' abilities pre- and postinstruction in order to understand how many students actually achieved an improvement in their abilities and whether or not a majority of students have moved to postabilities significantly greater than the national average.

This article reports on an investigation into the correlations between students' understandings of introductory astronomy concepts and the correctness and coherency of their written responses to targeted Lecture-Tutorial questions.

Light and spectroscopy are among the most important and frequently taught topics in introductory college-level general education astronomy courses (hereafter Astro 101). This is due to the fact that the vast majority of observational data studied by astronomers arrives at Earth in the form of light. While there are many processes by which matter can emit and absorb light, Astro 101 courses typically limit their instruction to the Bohr model of the atom and electron energy level transitions. In this paper, we report on the development of a new "Lecture-Tutorial" to help students learn about other processes that are responsible for the emission and absorption of light, namely molecular rotations, molecular vibrations, and the acceleration of charged particles by magnetic fields. Note that this paper primarily focuses on describing the variety of representations and reasoning tasks designed for this "Lecture-Tutorial"; while the end of this paper highlights some data that are suggestive of the "Lecture-Tutorial's" effectiveness, our more comprehensive analysis of its efficacy will be presented in a future publication.

What are the underlying worldviews and beliefs about the role of science in society held by students enrolled in a college-level, general education, introductory astronomy course (Astro 101)--and are those beliefs affected by active engagement instruction shown to significantly increase students' conceptual knowledge and reasoning abilities related to astronomy? To help answer this question, we administered Cobern's (Cobern 2001) "Thinking About Science Survey Instrument" (TSSI) to an Astro 101 class in the spring 2011. The TSSI probes students' beliefs about the relationship between science and many aspects of contemporary society. In this paper, we analyze the 442 pre-instruction and 294 post-instruction student responses we received to the TSSI. Many students select responses to the TSSI's items indicating they have positive views about the role of science in society. We also see a slight increase in the number of positive responses pre- to post-instruction. While there are limitations to the inferences one can draw from responses to a Likert scale survey such as the TSSI, this work nevertheless provides an important first step in a larger project to understand and affect the worldviews of general education, introductory astronomy students. To better interpret the significance of these results, we conclude by comparing the TSSI data to preliminary data from a related study in which we collected students' written responses to a series of provocative, open-ended prompts on the relationship between science and society. (Contains 12 tables and 9 figures.)

The Zooniverse projects turn everyday people into "citizen scientists" who work online with real data to assist scientists in conducting research on a variety of topics related to galaxies, exoplanets, lunar craters, and solar flares, among others. This paper describes our initial study to assess the conceptual knowledge and reasoning abilities of citizen scientists participating in two Zooniverse projects: Galaxy Zoo and Moon Zoo. In order to measure their knowledge and abilities, we developed two new assessment instruments, the Zooniverse Astronomical Concept Survey (ZACS) and the Lunar Cratering Concept Inventory (LCCI). We found that citizen scientists with the highest level of participation in the Galaxy Zoo and Moon Zoo projects also have the highest average correct scores on the items of the ZACS and LCCI. However, the limited nature of the data provided by Zooniverse participants prevents us from being able to evaluate the statistical significance of this finding, and we make no claim about whether there is a causal relationship between one's participation in Galaxy Zoo or Moon Zoo and one's level of conceptual understanding or reasoning ability on the astrophysical topics assessed by the ZACS or the LCCI. Overall, both the ZACS and the LCCI provide Zooniverse's citizen scientists with items that offer a wide range of difficulties. Using the data from the small subset of participants who responded to all items of the ZACS, we found evidence suggesting the ZACS is a reliable instrument (alpha = 0.78), although twenty-one of its forty items appear to have point biserials less than 0.3. The work reported here provides significant insight into the strengths and limitations of various methods for administering assessments to citizen scientists. Researchers who wish to study the knowledge and abilities of citizen scientists in the future should be sure to design their research methods to avoid the pitfalls identified by our initial findings. (Contains 3 tables, 9 figures, and 1 note.)

This paper is the first in a series of investigations into the data from the recent national study using the Light and Spectroscopy Concept Inventory (LSCI). In this paper, we use classical test theory to form a framework of results that will be used to evaluate individual item difficulties, item discriminations, and the overall reliability of the LSCI. We perform an analysis of individual students' normalized gains, providing further insight into the prior results from this data set. This investigation allows us to better understand the efficacy of measuring student achievement using the LSCI. Future papers will discuss our investigation of the data from the recent national study using item response theory (IRT). (Contains 8 figures and 1 table.)

This is the third of five papers detailing our national study of general education astronomy students' conceptual and reasoning difficulties with cosmology. In this paper, we use item response theory to analyze students' responses to three out of the four conceptual cosmology surveys we developed. The specific item response theory model we use is known as the partial credit model. Since readers may be unfamiliar with the partial credit model, we provide a pedagogical introduction to this model. We use the partial credit model to assess the reliabilities of the four survey forms and to determine the probabilities of students achieving different scores on survey items. (Contains 3 tables and 12 figures.) [For Part II, see EJ956292.]

This is our fourth paper in our five paper series describing our national study of general education astronomy students' conceptual and reasoning difficulties with cosmology. While previous papers in this series focused on the processes by which we collected and quantitatively analyzed our data, this paper presents the most common pre-instruction conceptual and reasoning difficulties identified from our qualitative analysis of students' written responses. We discuss students' naive ideas about the expansion and evolution of the universe, the Big Bang, interpreting Hubble plots, and the evidence for dark matter in spiral galaxies. (Contains 10 figures.) [For Part III, see EJ971055.]

This is the final paper in a five-paper series describing our national study of the teaching and learning of cosmology in general education astronomy college-level courses. A significant portion of this work was dedicated to the development of five new "Lecture-Tutorials" that focus on addressing the conceptual and reasoning difficulties that our research shows students have with frequently taught cosmology topics, such as the expansion of the universe, the Big Bang, and dark matter. We conducted a systematic investigation of the implementation of these new "Lecture-Tutorials" and resulting learning gains in order to test the efficacy of these new "Lecture-Tutorials." Our investigation included classroom observations, results from pre-post testing using four conceptual cosmology surveys, and comparisons between classes in terms of the class time spent on cosmology topics and other instructional strategies used to teach cosmology. We used this combination of qualitative and quantitative research results to evaluate the conceptual understandings of students who used the new cosmology "Lecture-Tutorials" compared to those students who did not. The analysis of our data shows that, in many cases, classrooms that used the cosmology "Lecture-Tutorials" saw a greater increase in their students' conceptual cosmology knowledge compared to classrooms that did not use the cosmology "Lecture-Tutorials." However, our results also indicate how instructors implement the "Lecture-Tutorials" into their classrooms strongly influences their students' learning gains. (Contains 2 tables and 4 figures.) [For Part IV, see EJ971054.]

This is the second of five papers detailing our national study of general education astronomy students' conceptual and reasoning difficulties with cosmology. This article begins our quantitative investigation of the data. We describe how we scored students' responses to four conceptual cosmology surveys, and we present evidence for the inter-rater reliability of those scores. We devote the bulk of this article to a classical test theory analysis of the data. We calculate difficulties and discriminations for each item, and we compute Cronbach's [alpha] as a measure of the reliability of the surveys. We also discuss the implications this analysis has for the validity of the surveys. (Contains 5 tables.) [For Part I, see EJ956291.]

This is the first in a series of five articles describing a national study of general education astronomy students' conceptual and reasoning difficulties with cosmology. In this paper, we describe the process by which we designed four new surveys to assess general education astronomy students' conceptual cosmology knowledge. These surveys focused on the expansion and evolution of the universe, the Big Bang, and the evidence for dark matter in spiral galaxies. We also present qualitative evidence for the validity of these surveys. (Contains 6 tables and 2 figures.)

This study presents and interprets some conceptual difficulties junior-level physics students experience with Ampere's law. We present both quantitative data, based on students' written responses to conceptual questions, and qualitative data, based on interviews of students solving Ampere's law problems. We find that some students struggle to connect the current enclosed by an Amperian loop to the properties of the magnetic field while some students do not use information about the magnetic field to help them solve Ampere's law problems. In this paper, we show how these observations may be interpreted as evidence that some students do not see the integral in Ampere's law as representing a sum and that some students do not use accessible information about the magnetic field as they attempt to solve Ampere's law problems. This work extends previous studies into students' difficulties with Ampere's law and provides possible guidance for instruction. (Contains 6 figures.)

Although concept inventories are among the most frequently used tools in the physics and astronomy education communities, they are rarely evaluated using item response theory (IRT). When IRT models fit the data, they offer sample-independent estimates of item and person parameters. IRT may also provide a way to measure students' learning gains that circumvents some known issues with Hake's normalized gain. In this paper, we review the essentials of IRT while simultaneously applying it to the Star Properties Concept Inventory. We also use IRT to explore an important psychometrics debate that has received too little attention from physics and astronomy education researchers: What do we mean when we say we "measure" a mental process? This question leads us to use IRT to address the provocative question that constitutes the title of this paper: Do concept inventories actually measure anything? (Contains 18 figures and 9 tables.)

Decades of research show that students learn more in classes that utilize active learning than they do in traditional, lecture-only classes. Active learning also reduces the achievement gaps that are often present between various demographic groups. Given these well-established results, instructors of upper-division astronomy courses may decide to search the astronomy education research literature in hopes of finding some guidance on common student difficulties, as well as research-validated and research-based active learning curricula. Their search will be in vain. The current literature on upper-division astronomy is essentially non-existent. This is a shame, since many upper-division astronomy students will experience conceptual and problem-solving difficulties with the quantitative problems they encounter. These difficulties may exist even if students have a strong background in mathematics. In this paper, I examine one quantitative problem that is representative of those that upper-division astronomy students are expected to solve. I list many of the subtle pieces of information that students need to understand in order to advance toward a solution and I describe how such a list can be used to generate Peer Instruction (PI) questions. I also provide guidelines for instructors who wish to develop and implement their own PI questions. These PI questions can be used to increase the amount of active learning that occurs in an upper-division astronomy course. They help develop students' understandings of symbolic, mathematical representations, and they help improve students' problem-solving skills. The ideas presented in this paper can help instructors infuse their upper-division astronomy courses with active learning. [ABSTRACT FROM AUTHOR]

We report the results of a large-scale study of the state of science content knowledge of volunteers in Galaxy Zoo (www.galaxyzoo.org), an online citizen science project in which public volunteers classify galaxies in an effort to benefit cutting-edge astronomy research. We were interested in whether participating in Galaxy Zoo leads to any increase in participants' astrophysical content knowledge. To assess volunteer content knowledge, we examined the responses of 1476 Galaxy Zoo volunteers to 32 conceptually challenging multiple-choice questions. We looked for any relationships between participants' assessment scores and the number of galaxies classified upon answering the first assessment question, the number of galaxies classified between their first response and their final response to the assessment, and the length of time since they first created their Galaxy Zoo account. All relationships were of small effect size. These results suggest that participation in the project's central galaxy classification task, in and of itself, is not associated with increased astrophysical content knowledge. We strongly recommend that future studies of online citizen science environments examine how volunteers take advantage of opportunities to develop their knowledge and skills outside of the self-contained central task, especially in the context of opportunities for interactions with other volunteers. [ABSTRACT FROM AUTHOR]

In this paper, we describe how we transformed our large-enrollment introductory physics sequence for the life sciences to a Lecture/Studio format and aligned the physics concepts with authentic biological applications. We modified the pedagogy to include research-validated practices in interactive engagement, and accomplished our goals of enhanced learning gains and institutionalization of our course transformations. The active engagement at the heart of the Lecture/Studio format results in comparable or enhanced learning gains (as measured by validated concept surveys) when compared to traditional instruction. As a result of our efforts, the current format of these courses is sustainable, requiring no greater financial or human resources than does the traditional mode of teaching such courses. We developed a complete suite of active-engagement instructional materials and made them available to the physics education community for adoption outside our institution. [ABSTRACT FROM AUTHOR]

The detection and study of extrasolar planets is an exciting and thriving field in modern astrophysics and an increasingly popular topic in introductory astronomy courses. One detection method relies on searching for stars whose light has been gravitationally microlensed by an extrasolar planet. In order to facilitate instructors' abilities to bring this interesting mix of general relativity and extrasolar planet detection into the introductory astronomy classroom, we have developed a new Lecture-Tutorial called "Detecting Exoplanets with Gravitational Microlensing." In this paper, we describe how this new Lecture-Tutorial's representations of astrophysical phenomena, which we selected and created based on theoretically motivated considerations of their pedagogical affordances, are used to help introductory astronomy students develop more expert-like reasoning abilities. [ABSTRACT FROM AUTHOR]

Physics instructors can enrich, enliven, and enhance their courses with conceptually rich cosmology content. In this paper, we specifically discuss how instructors can integrate lessons on Hubble's law (as it relates to the expansion of the universe and dark energy) and spiral galaxies' rotation curves (as they relate to the presence of dark matter) into an introductory, college-level course on mechanics. These cosmology topics intersect with the content of introductory physics in a number of areas, such as students' abilities to read and interpret graphs and their conceptual understandings of both kinematics and dynamics. Throughout this paper, we draw upon the results from, and research-validated curricula informed by, physics and astronomy education research. In particular, we feature the results from a national study we recently completed with introductory college-level general education astronomy students on the teaching and learning of cosmology. [ABSTRACT FROM AUTHOR]

Heating processes inside large black holes can produce tremendous amounts of entropy. Locality requires that this entropy adds on space-like surfaces, but the resulting entropy (1010 times the Bekenstein-Hawking entropy in an example presented in the companion paper) exceeds the maximum entropy that can be accommodated by the black hole's degrees of freedom. Observer complementarity, which proposes a proliferation of non-local identifications inside the black hole, allows the entropy to be accommodated as long as individual observers inside the black hole see less than the Bekenstein-Hawking entropy. In the specific model considered with huge entropy production, we show that individual observers do see less than the Bekenstein-Hawking entropy, offering strong support for observer complementarity. [ABSTRACT FROM AUTHOR]