Edward E. Prather

Research on a Lecture-Tutorial Approach to Teaching Introductory Astronomy for Non-Science Majors

The Lecture-Tutorial curriculum development project produced a set of 29 learner-centered classroom instructional materials for a large- enrollment introductory astronomy survey course for non-science majors. The Lecture-Tutorials are instructional materials intended for use by collaborative student learning groups, and are designed to be integrated into existing courses with conventional lectures. These instructional materials offer classroom-ready learner-centered activities that do not require any outside equipment or drastic course revision for implementation. Each 15-minute Lecture-Tutorial poses a sequence of conceptually challenging, Socratic dialogue-driven questions, along with graphs and data tables, all designed to encourage students to reason critically about difficult concepts in astronomy. The materials are based on research into student beliefs and reasoning difficulties, and use proven instructional strategies. The Lecture-Tutorials have been field- tested for effectiveness at various institutions, which represent a wide range of student populations and instructional settings. In addition to materials development, a second effort of this project focused on the assessment of changes in students’ conceptual understanding and attitudes toward learning astronomy as a result of both lecture and the subsequent use of Lecture-Tutorials. Quantitative and qualitative assessments were completed using a precourse,

Development and Validation of the Light and Spectroscopy Concept Inventory.

This article describes the development and validation of the Light and Spectroscopy Concept Inventory (LSCI), a 26-item diagnostic test designed (1) to measure students’ conceptual understanding of topics related to light and spectroscopy, and (2) to evaluate the effectiveness of instructional interventions in promoting meaningful learning gains in an introductory college astronomy course. We also present the final field- tested version of the LSCI for general use by the astronomy education community.

A national study assessing the teaching and learning of introductory astronomy. Part I. The effect of interactive instruction

We present the results of a national study on the teaching and learning of astronomy as taught in general education, non-science-major, introductory astronomy courses. Nearly 4000 students enrolled in 69 sections of courses taught by 36 different instructors at 31 institutions completed (pre- and post-instruction) the Light and Spectroscopy Concept Inventory (LSCI) from Fall 2006 to Fall 2007. The classes varied in size and were from all types of institutions, including 2- and 4-year colleges and universities. Normalized gain scores for each class were calculated. Pre-instruction LSCI scores were clustered around ∼25%, independent of class size and institution type, and normalized gain scores varied from about −0.07 to 0.50. To estimate the fraction of classroom time spent on learner-centered, active-engagement instruction we developed and administered an Interactivity Assessment Instrument (IAI). Our results suggest that the differences in gains were due to instruction in the classroom, not the type of c...

Hints of a Fundamental Misconception in Cosmology

To explore the frequency and range of student ideas regarding the Big Bang, nearly 1,000 students from middle school, secondary school, and college were surveyed and asked if they had heard of the Big Bang and, if so, to describe it. In analyzing their responses, we uncovered an unexpected result that more than half of the students who stated that they had heard of the Big Bang also provided responses that suggest they believe that the Big Bang was a phenomenon that organized pre-existing matter. To further examine this result, a second group of college students was asked specifically to describe what existed or occurred before, during, and after the Big Bang. Nearly 70% gave responses clearly stating that matter existed prior to the Big Bang. These results are interpreted as strongly suggesting that most students are answering these questions by employing an internally consistent element of knowledge or reasoning (often referred to as a phenomenological primitive, or p-prim), consistent with the idea that you can’t make something from nothing. These results inform the debate about the extent to which college students have pre-existing notions that are poised to interfere with instructional efforts about contemporary physics and astronomy topics.

Teaching and learning astronomy in the 21st century

A national study of teaching and learning in courses that introduce astronomy to nonscience majors shows that interactive learning strategies can significantly improve student understanding of core concepts in astrophysics.

Effectiveness of Collaborative Ranking Tasks on Student Understanding of Key Astronomy Concepts

This research concerns the development and assessment of a program of introductory astronomy conceptual exercises called ranking tasks. These exercises were designed based on results from science education research, learning theory, and classroom pilot studies. The investigation involved a single-group repeated measures experiment across eight key introductory astronomy topics with 253 students at the University of Arizona. Student understanding of these astronomy topics was assessed before and after traditional instruction in an introductory astronomy course. Collaborative ranking tasks were introduced after traditional instruction on each topic, and student understanding was evaluated again. Results showed that average scores on multiple-choice tests across the eight astronomy topics increased from 32% before instruction, to 61% after traditional instruction, to 77% after the ranking- task exercises. A Likert scale attitude survey found that 83% of the students participating in the 16-week study thought that the rankingtask exercises helped their understanding of core astronomy concepts. Based on these results, we assert that supplementing traditional lecture- based instruction with collaborative ranking-task exercises can significantly improve student understanding of core astronomy topics.

Students' beliefs about the role of atoms in radioactive decay and half-life

Contemporary science education research emphasizes the importance of considering students pre-instructional beliefs when designing effective, learner-centered instructional strategies. When scientists teach about dating geological events, most often the concepts of radioactive decay and half-life are presented. However, the research base on student understanding of radiation and radioactivity is currently quite limited. The principal research question used to focus this investigation asked: What are the common difficulties that students experience when trying to learn about radiation and radioactivity? Our research illustrates that students bring to the classroom many inaccurate ideas and reasoning difficulties on the topics of ionizing radiation, radioactivity, and radioactive decay that are well-poised to interfere with students understanding of how half-life is used to determine geologic time. To uncover the range and frequency of the dominant student beliefs, we performed individual demonstration interviews and administered open-response and multiple-choice conceptual tests to students from a wide-range of science backgrounds. Our results show that students are often unable to differentiate between the ideas of irradiation and contamination, and that many of these students reasoning difficulties about radioactive decay and half-life stem from their inaccurate mental models regarding the atom.

A National Study Assessing the Teaching and Learning of Introductory Astronomy Part II: The Connection between Student Demographics and Learning

This is the second in a series of reports on a national study of the teaching and learning of astronomy in general education, nonscience major, introductory college astronomy courses hereafter referred to as Astro 101. The analysis reported here was conducted using data from nearly 2000 students enrolled in 69 Astro 101 classes taught across the country. These students completed a 15-question demographic survey, in addition to completing the 26-question Light and Spectroscopy Concept Inventory LSCI pre- and post-instruction. The LSCI was used to determine students’ learning via a normalized gain calculated for each student. A multivariate regression analysis was conducted to determine how ascribed characteristics personal demographic and family characteristics, achieved characteristics academic achievement and student major, and the use of interactive learning strategies are related to student learning in these classes. The results show dramatic improvement in student learning with increased use of interactive learning strategies even after controlling for individual characteristics. In addition, we find that the positive effects of interactive learning strategies apply equally to men and women, across ethnicities, for students with all levels of prior mathematical preparation and physical science course experience, independent of GPA, and regardless of primary language. These results powerfully illustrate that all categories of students can benefit from the effective implementation of interactive learning strategies.

Analysis of the Astronomy Diagnostic Test

Seventy undergraduate class sections were examined from the database of Astronomy Diagnostic Test (ADT) results of Deming and Hufnagel to determine if course format correlated with ADT normalized gain scores. Normalized gains were calculated for four different classroom scenarios: lecture, lecture with discussion, lecture with lab, and lecture with both lab and discussion. Statistical analysis shows that there are no significant differences in normalized gain among the self- reported classroom formats. Prerequisites related to mathematics courses did show differences in normalized gain. Of all reported course activities, only the lecture and the readings for the course correlate significantly with the normalized gain. This analysis suggests that the ADT may not have enough sensitivity to measure differences in the effectiveness of different course formats because of the wide range of topics that the ADT addresses with few questions. Different measures of gain and their biases are discussed. We argue that the use of the normalized gain is not always warranted because of its strong bias toward high pretest scores.

Development and Validation of the Star Properties Concept Inventory

Concept inventories (CIs)—typically multiple-choice instruments that focus on a single or small subset of closely related topics—have been used in science education for more than a decade. This paper describes the development and validation of a new CI for astronomy, the Star Properties Concept Inventory (SPCI). Questions cover the areas of stellar properties (focussing primarily on mass, temperature, luminosity, and lifetime), nuclear fusion, and star formation. Distracters were developed from known alternative conceptions and reasoning difficulties commonly held by students. The SPCI was tested through an iterative process where different testing formats (open-ended, multiple-choiceu2009+u2009explain, and multiple-choice) were compared to ensure that the distracters were in fact the most common among the testing population. Content validity was established through expert reviews by 26 astronomy instructors. The SPCI Version 3 was then tested in multiple introductory undergraduate astronomy courses for non-science majors. Post-test scores (out of 23 possible) were significantly greater (Mu2009=u200911.8, SDu2009=u20093.87) than the pre-test scores (Mu2009=u20097.09, SDu2009=u20092.73). The low post-test score—only 51.3%—could indicate a need for changing instructional strategies on the topics of stars and star formation.