Student Understanding of Gravity in Introductory College Astronomy

Abstract

Twenty-four free-response questions were developed to explore introductory college astronomy students' understanding of gravity in a variety of contexts, including in and around Earth, throughout the solar system, and in hypothetical situations. Questions were separated into three questionnaires, each of which was given to a section of introductory college astronomy with 143, 137, and 32 respondents, respectively. Combined with 15 interviews, the exploratory, open-response format allowed themes to emerge naturally, with both documented and undocumented misconceptions observed. The breadth of questions allowed for descriptions of possible student mental frameworks, including alternative models and misapplication of the scientific model.

Applicability of the Newtonian gravity concept inventory to introductory college physics classes

“…Indeed, Supplement A shows overall very similar functioning of distractor choices for both physics and astronomy students, and Supplement B links the specific mental models discussed in the Background (and in Ref. 15) to interviewee's individual thought patterns.…”

“…Physics instructors and researchers can gain some insights about their students' understanding of gravity by assessing students' understanding of forces using existing assessments such as the Force Concept Inventory, 14 but these tend to focus on the effects of gravity on or near Earth's surface. Our research on astronomy students has illustrated that there are unique reasoning difficulties related to thinking about gravity that are beyond difficulties related to forces in general, 15 however, research on the prevalence of these gravityspecific reasoning difficulties within the physics population has not been previously conducted. This paper investigates the applicability of the NGCI as an appropriate and useful tool for assessing the conceptual and reasoning difficulties with physics students.…”

“…15,20 We discuss the conceptual focus of the NGCI along four domains (Directionality, Force Law, Independence of Other Forces, and Threshold) and argue for the applicability of these domains across both the astronomy and physics curricula. Next, in the Method Section, we establish the applicability of the NGCI to physics courses through testing the NGCI with a large sample of physics students at eight colleges and universities across the United States, providing a dataset of 1,392 pre-instruction responses and 929 post-instruction responses.…”

“…Our previous publications 15,20 24 piloted iteratively with astronomy students, and evaluated using a set of commonly accepted methods for evaluation of multiplechoice conceptual surveys. 6,[11][12][13]25 Three survey iterations resulted in the full 26-item Newtonian Gravity Concept Inventory (NGCI).…”

Development of a Learning Progression for the Formation of the Solar System

“…The literature includes a close examination of student thinking around certain elements of this big idea, such as the nature of gravity (e.g. Williamson & Willoughby, 2012) and planetary orbits (e.g. Yu, Sahami, & Denn, 2010), without considering how these ideas fit together as part of a coherent big idea or characterizing student thinking as a progression of increasingly sophisticated versions of the scientific concept.…”