Using Visualizations and Representations to Teach and Learn Chemistry

Organizers: Mary B. Nahkleh and Jessica Weller, Department of Chemistry, Purdue University, West Lafayette, IN 47907, tel: (765) 494-5314, Email: mnakhleh@purdue.edu and wellerj@purdue.edu  

The symposium “Using Visualizations and Representations to Teach and Learn Chemistry,” was held as part of the Division of Chemical Education program at the 241st American Chemical Society National Meeting and Exposition, Anaheim CA. The symposium provided an opportunity for researchers in the area of visualization (broadly defined) to report their research findings and to further define and extend this area of chemical education research. The symposium consisted of both a morning and afternoon section.

Jessica Weller (co-author Mary Nakhleh) started the symposium by describing her project on undergraduates’ external representations (drawings) of their internal representations of matter. Fourteen undergraduates enrolled in general chemistry courses were interviewed about their drawings of matter in the solid, liquid and gas phases. Students spontaneously drew four different types of representations, which enabled the researchers to develop rubrics for these different classifications of student representations. These data were compared to data previously collected from elementary, middle and high school students.

Mike Stieff (co-authors Ghislain Deslongchamps & Mary Hegarty) then discussed representational competence in multi-representational molecular animations in organic chemistry undergraduates. These students were allowed to use multi-representational molecular mechanics Flash animation in a problem-solving interview. Data were analyzed using both protocol analysis and eye fixation. The researchers report that students seemed to rely mainly on two visual-spatial representations in the display and did not utilize the accompanying mathematical representations. Further, the verbal protocols and eye movement data were highly correlated, suggesting that these two functions reflect similar cognitive processes.

Nahyr Rovira-Figueroa (co-author Mary Nakhleh) continued the emphasis on molecular level understanding by reporting on her study of undergraduates’ representations of chemical equilibrium in the context of laboratory learning. However, she expanded the discussion to include Alex Johnstone’s triangle model of the three levels of chemistry: the macroscopic, the molecular & and the symbolic. Student-constructed concepts maps were used in conjunction with semi-structured student interviews as a way to provide a 2D-representation of students’ content knowledge and representational levels. She created a concept map scoring rubric to (1) qualitatively describe the concept map configuration, (2) quantitatively analyze the accuracy of the map links and (3) classify the links according to Johnstone’s three representational levels.

Kimberly Linenberger (co-author Stacey Lowery Bretz) expanded the conversation into the area of biochemistry. She investigated undergraduate students’ understanding of enzyme-substrate interactions using textbook representations of both the lock and key and induced fit models. She reported that an understanding gap may exist between students and professors because professors strongly favor the induced fit model but students have previously learned the lock and key model. She developed the Enzyme-Substrate Interactions Concept Inventory from her research findings.

Cynthia J. Luxford (co-author Stacey Lowery Bretz) investigated high school, undergraduate and graduates students’ understanding of ionic and covalent bonding on the symbolic and particulate levels. She used a five-phase interactive interview to probe these students’ understanding of bonding through the use of multiple representations. Analysis of the data revealed that students were able to identify key features encoded in each type of representation.

Lihua Wang discussed a new method for teaching group theory analysis of the infrared spectra of organometallic compounds using molecular modeling. The main focus of this method is to enhance students’ understanding of the symmetry properties of vibrational modes and the process of group theory analysis of IR spectra by using visual aids provided by computer molecular modeling. Results of sample calculations using semi-empirical and density functional theory methods were presented, and a limited amount of feedback from students was also presented.

Kereen Monteyne (co-author Erin Rowan) used questions embedded in written and online assessments to investigate how undergraduate students were able to interpret and link particulate representations to their corresponding symbolic forms. The questions were drawn from the published literature or developed by the research team. The finding of this study provide a measurement of the extent to which different populations of students can interpret and link particulate representations to their corresponding symbolic forms.

Scott Hinze (co-authors Vickie M. Williamson, Kenneth C. Williamson, Mary Shultz, David Rapp & Ghislain Deslongchamps) reported on a study that investigated whether individual differences among beginning organic students might influence the effectiveness of visualizations. They were particularly interested in ball-and-stick vs. potential plot representations in the context of alcohols, carboxylic acids and hydroxycarboxlyic acids. The students were given a pre-test to determine prior knowledge; from this pool 30 students were selected based on high or low prior knowledge. These students were tested for reasoning ability, spatial ability and need for cognition. Students also participated in an eye-tracking session that involved using both ball-and-stick and potential plot representations. Eye movement patterns indicated that students relied on the more familiar ball-and-stick representations, especially for the more difficult questions. Students’ choices of representation were also moderated by individual differences in prior knowledge, reasoning abilities and spatial abilities.

Michael J. Sanger (co-author Deborah R. Rosenthal) investigated how using 3-D and 2-D animations in conjunction with real-time redox/electrochemical demonstration might impact students’ abilities to describe the chemical processes that were occurring. The presentation focused on students’ explanations of key concepts and how these explanations might have changed as a result of viewing the demonstration and animations. Also, the researchers used the data to determine how the two animations affected students’ conceptions and if the order of viewing had changed students’ conceptions.

John Pollard (co-author Vincente Talanquer) shifted the focus to using visualization tools and activities as part of a new general chemistry curriculum. They argue that the focus of introductory general chemistry courses should shift from learning chemistry as a body of knowledge to understanding chemistry as a way of thinking. The central goals of the curriculum that was presented were: to promote deeper conceptual understanding of a minimum core of fundamental ideas; to connect core ideas between the course units; to introduce students to modern ways of thinking and problem solving; to involve students in realistic decision making and problem solving activities.

Jennifer T. Ellis used real-world examples to enhance students’ visual and conceptual understanding of dimensional analysis. She provided real world visual examples of units and how to relate these examples to dimensional analysis problem solving.

David S. Katz’s paper was withdrawn.