Directed or Random? Student Reasoning about Diffusion across Contexts

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Bibliographic Details
Title: Directed or Random? Student Reasoning about Diffusion across Contexts
Language: English
Authors: Aeryn L. VanDerSlik (ORCID 0009-0007-6590-2602), Emily E. Scott, Mary Pat Wenderoth, Zachary A. Kam, Jasmine D. Parker, Maya B. Shah, Joseph Vieregge, Jennifer H. Doherty (ORCID 0000-0002-2333-1692)
Source: Advances in Physiology Education. 2025 49(4):1014-1025.
Availability: American Physiological Society. 9650 Rockville Pike, Bethesda, MD 20814-3991. Tel: 301-634-7164; Fax: 301-634-7241; e-mail: webmaster@the-aps.org; Web site: https://www.physiology.org/journal/advances
Peer Reviewed: Y
Page Count: 12
Publication Date: 2025
Sponsoring Agency: National Science Foundation (NSF)
Contract Number: 1661263
Document Type: Journal Articles
Reports - Research
Education Level: Higher Education
Postsecondary Education
Descriptors: Thinking Skills, Physiology, Scientific Concepts, Motion, Context Effect, Reliability, Public Colleges, Research Universities, Problem Solving, Science Education, Knowledge Level, Undergraduate Students
DOI: 10.1152/advan.00185.2025
ISSN: 1043-4046
1522-1229
Abstract: Diffusion is a critical component of the Physiology Core Concept of flow down gradients and is fundamental to understanding how ions, gases, or signaling molecules travel short distances in the body. When asked about diffusion, students often reason successfully using the "things move from areas of high to low concentration" heuristic but struggle to understand that random motion underlies this movement. We investigated the different knowledge resources students use when reasoning about diffusion across different contexts. Additionally, we determined if item context impacted the resources students activated and how consistent students were in their reasoning. We gave students a pair of questions from three contexts (plant, animal, and nonliving) that asked them to predict and explain where a molecule of gas would be located before and after equilibrium. Using the resources framework, we identified 14 common knowledge resources and 6 different patterns in resource activation. "High to low" and related resources were used in 73% of responses. Only 23% of responses included at least one "random motion" resource, and the vast majority of these responses described random particle motion starting only after equilibrium is reached. Item context did not significantly affect the resources students used. Students were also mostly consistent in their reasoning, with 76% using similar resources across the two items. These findings indicate that "high to low" and related resources have a high cueing priority for many students and that instructors should help students unpack random motion as the mechanism underlying diffusion instead of leaving it "black boxed."
Abstractor: As Provided
Entry Date: 2025
Accession Number: EJ1490867
Database: ERIC
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Description
Abstract:Diffusion is a critical component of the Physiology Core Concept of flow down gradients and is fundamental to understanding how ions, gases, or signaling molecules travel short distances in the body. When asked about diffusion, students often reason successfully using the "things move from areas of high to low concentration" heuristic but struggle to understand that random motion underlies this movement. We investigated the different knowledge resources students use when reasoning about diffusion across different contexts. Additionally, we determined if item context impacted the resources students activated and how consistent students were in their reasoning. We gave students a pair of questions from three contexts (plant, animal, and nonliving) that asked them to predict and explain where a molecule of gas would be located before and after equilibrium. Using the resources framework, we identified 14 common knowledge resources and 6 different patterns in resource activation. "High to low" and related resources were used in 73% of responses. Only 23% of responses included at least one "random motion" resource, and the vast majority of these responses described random particle motion starting only after equilibrium is reached. Item context did not significantly affect the resources students used. Students were also mostly consistent in their reasoning, with 76% using similar resources across the two items. These findings indicate that "high to low" and related resources have a high cueing priority for many students and that instructors should help students unpack random motion as the mechanism underlying diffusion instead of leaving it "black boxed."
ISSN:1043-4046
1522-1229
DOI:10.1152/advan.00185.2025