Geraldine L. Cochran

A Multi-Institutional Investigation of Students' Preinstructional Ideas about Cosmology.

In order to improve instruction in introductory astronomy, we are investigating students’ preinstructional ideas about a number of cosmology topics. This article describes one aspect of this large research study in which 1270 students responded to a subset of three questions each from a larger set of questions about the following areas: definition of a light-year and the structure, composition, and evolution of the Universe. Within structure, we investigated students’ ideas about definitions or descriptions of Solar System, Galaxy, Universe, and the relationships among them. Composition included the formation of chemical elements, dark matter, and dark energy, while evolution focused on the Big Bang Theory, age of the Universe, and how the Universe changes over time. Responses were iteratively coded for common themes. Major findings demonstrate that students commonly misidentify the light-year as a measurement of time, and that they provide incomplete definitions of common objects (Solar System, Galaxy) and the Universe itself, often conflating the terms. Generally speaking, students have little understanding of dark matter or dark energy, providing definitions that are superficial or do not answer the question. Consistent with previous research, we found students view the Big Bang as an explosion. Students’ ideas about the age of the Universe range from millions to trillions of years, but some students believe the Universe to be infinitely old. For both the age of the Universe and the Big Bang Theory, students are not familiar with the scientific evidence that exists, and in some cases do not believe such evidence can exist. Finally, students’ understanding of how the Universe changes over time is based largely on smaller changes of objects within it (e.g., stellar evolution) or the motions of objects (e.g., planetary orbits). These and other ideas provide fodder—both scientifically accurate and inaccurate—on which to build effective instruction. Particular attention should be paid to areas in which words that are used differently between our everyday vernacular and scientific language can create or reinforce alternative conceptions.

Investigating Student Ideas about Cosmology I: Distances and Structure.

Recently, powerful new observations and advances in computation and visualization have led to a revolution in our understanding of the structure of the Universe. As the field of cosmology advances, it is of interest to study how student ideas relate to scientific understanding. In this paper, we examine in-depth undergraduate students’ ideas on distances and structure in the Universe as students progress through a general education astronomy integrated lecture and laboratory course with a focus on active learning. The study was conducted over five semesters at an urban, minority-serving institution. The data collected include individual interviews (N1⁄4 15) and course artifacts (N 60), such as precourse homework essays, prelab surveys, and midterm and final exam questions in a variety of formats. We find that students are fairly successful at tasks involving relative distances, but struggle with absolute distances; have difficulty going beyond an elementary model of the Solar System as the Sun and planets; struggle to visualize galactic halos; but successfully increase their understanding of the hierarchical nature of structure in the Universe throughout the semester.

Evidence of Intuitive and Formal Knowledge in Student Responses: Examples from the Context of Dynamics

When presented with a question, students activate a set of knowledge, or schema, that they use to respond to the question. For many instructors, one of the goals of the introductory physics course is to help students build robust schemas of formal knowledge that are activated for a given task. In this paper, we present evidence that suggests that even when schemas of formal knowledge are formed, students often struggle to activate this knowledge. We focus on the analysis of interviews with two introductory physics students concerning the topic of dynamics. We also demonstrate that the act of explaining, during the interview, has a profound impact on the students’ responses.

Investigating Student Ideas about Cosmology II: Composition of the Universe.

Continuing our work from a previous study (Coble et al. 2013), we examine undergraduates’ ideas on the composition of the Universe as they progress through a general education astronomy integrated lecture and laboratory course with a focus on active learning. The study was conducted over five semesters at an urban minority-serving institution. The data collected include individual interviews (N1⁄4 15) and course artifacts (N 60), such as prelab surveys, and midterm and final exam questions in a variety of formats. We find that students easily obtain a superficial knowledge of the origins of the chemical elements and the existence of dark matter and dark energy, which they are generally unaware of pre-instruction. However, they are hindered in their ability to reproduce the argument for the existence of dark matter at least in part because of weaknesses in their graph-reading abilities.

Unique voices in harmony: Call-and-response to address race and physics teaching

In the February 2016 issue of The Physics Teacher, we announced a call for papers on race and physics teaching. The response was muted at first, but has now grown to a respectable chorale-sized volume. As the manuscripts began to come in and the review process progressed, Geraldine Cochran graciously agreed to come on board as co-editor for this remarkable collection of papers, to be published throughout the fall of 2017 in TPT. Upon reviewing the original call and the responses from the physics community, the parallels between generating this collection and the grand call-and-response tradition became compelling. What follows is a conversation constructed by the co-editors that is intended to introduce the reader to the swell of voices that responded to the original call. The authors would like to thank Pam Aycock for providing many useful contributions to this editorial.

Women in physics in the United States: recruitment and retention

Initiatives to increase the number, persistence, and success of women in physics in the US reach pre-teen girls through senior women. Programs exist at both the local and national levels. In addition, researchers have investigated issues related to gender equity in physics and physics education. Anecdotal evidence suggests increased media coverage of the underrepresentation of women in science. All of these efforts are both motivated and made more effective by the collection and presentation of data on the presence, persistence, and promise of women in physics.

Understanding and Encouraging Effective Collaboration in Introductory Physics Courses

Anecdotal evidence from the introductory physics classrooms at Chicago State University suggests that our students view collaboration as an important tool in their learning. Despite this, students often need additional instruction and support in order for collaboration to be effective. In order to aid students in establishing effective collaborations we may be able to capitalize on the fact that students at CSU readily accept the inquiry approach to instruction. In this paper, we present the initial stage of this work. Specifically, we have begun to videotape student interactions in the classroom, interview students about the nature of learning, and develop and administer instruments that assess the value students place on the use of guided inquiry. By utilizing a specific criteria and analyzing the occurrence of specific behaviors in the classroom we can determine the effectiveness of collaboration during group work. Responses regarding how students value the use of questions in instruction indicate the ...