P369: Investigating students’ understanding of ionic solids in chemistry with the use of 2D and 3D representations


Author: Jessica Malinchak, California State University Fullerton, USA

Co-Author: Barbara L. Gonzalez, California State University, Fullerton, USA; Kereen Monteyne, Northern Kentucky University, USA

Date: 8/4/14

Time: 6:00 PM7:15 PM

Room: KC

Related Symposium: S33

Visual modeling is an essential tool for teaching science because many concepts involve the understanding of particles that cannot always be observed with the naked eye or even with the assistance of current technology. Chemistry relies heavily on the use of two-dimensional (2D) models to represent the inherently three-dimensional (3D) molecules. Effective models increase students’ representational competence, which is the ability to communicate, think, and practice learned knowledge experimentally. Representational competence encompasses the connection between the visual model and the abstract concept represented. One aspect of representational competence is determining whether there is a difference between students’ comprehension when using 2D compared to 3D representations. The purpose of this study is to assess the effect of using 2D versus 3D representations to visually model ionic compounds during physical and chemical changes at the particulate level. The subjects of this study were students who were enrolled in a General Chemistry I course during the Fall 2012, Spring 2013, and Spring 2014 semesters in Southern California. Students’ answers from a pre-lab and a post-lab activity that deals with the physical and chemical change of ionic solids with the use of visual representations were evaluated. Data analysis includes a comparison of mean scores by independent samples t-tests. Preliminary results show that students score higher on assessments with 2D than 3D representations of ionic solids. This study may serve as a precursor to the development of an assessment of representational competence.

P52: C3Lab: An integrated cognitive and conceptual curriculum for the general chemistry laboratory

Author: Barbara L. Gonzalez, California State University Fullerton, USA

Co-Author: Kereen Monteyne, Northern Kentucky University, USA; Jessica Malinchak, California State University Fullerton, USA

Date: 8/3/14

Time: 3:40 PM4:00 PM

Room: MAN 123

Related Symposium: S8

Investigators from Northern Kentucky University and California State University Fullerton, in an NSF-funded project, designed a series of integrated laboratory activities that scaffold students’ development of cognitive skills to support conceptual understanding in general chemistry laboratory. The activities target cognitive skills specific to inquiry-based learning in the laboratory, and the abilities of students to transform fundamental chemistry concepts between macroscopic, particulate and symbolic representations. A Learning Continuum Framework that describes a developmental progression of cognitive and conceptual learning objectives scaffolded across three inquiry approaches of structured, guided and open inquiry guides the development of the laboratory activities. The laboratory instructional materials focus on four concept domains: physical and chemical change, stoichiometry, solutions and gases. Preliminary results regarding students’ ability to correctly assign variable names, align uncertainty in measurement with significant figures, construct scientifically appropriate graphs and interpretation of two-dimensional versus three-dimensional models of ionic solids will be presented.