P154: Scratching the surface of chemistry: A progression for categorizing chemistry problems
: Stefan M. Irby and Andy L. Phu, Western Washington University, USA
Co-Author: Emily J. Borda, Western Washington University , USA
Time: 10:35 AM – 10:55 AM
Room: LTT 103
Related Symposium: S13
Chemistry can be a challenging subject for students to master. One possible reason for this is students may have difficulty thinking about chemistry problems in terms of underlying chemical principles. Studies have shown that students struggle with the ability to connect three levels of chemistry representation: 1) macroscopic-scale phenomena 2) sub-microscopic or small particle representations of phenomena and 3) symbolic representation of phenomena. A card-sort task was used to develop a system for placing individuals along a learning progression as they transition from segregating the three levels of representation towards linking them through common concepts. If a participant sorted the problems by representation it would be categorized as sorting by surface features. In contrast if a participant categorized the problems by the core concept and not by the representation would be an example of sorting by underlying principles. The task was given to participants ranging from no-chemistry experience to chemistry experts (professors). There is a distinct sorting pattern between no-chem and experts, as well as a steady progression as students move through the chemistry curriculum, gradually sorting more expert-like. Results from hierarchical agglomerative clustering analysis suggest the transition from sorting by surface features to sorting by underlying principles is not as straightforward as some have proposed. As students move through the chemistry curriculum, the problems are sorted as a complex hybrid of both categorization types while moving towards categorizing by underlying principles.
P89: Cognitive affordances of multiple external representations in a virtual chemistry lab
: Justin Haupt and Emily J. Borda, Western Washington University, USA
Co-Author: Stefan M. Irby and Andy L. Phu,Western Washington University, USA
Time: 4:20 PM – 4:40 PM
Room: LTT 103
Related Symposium: S13
Computer module labs replaced five “wet” labs for a first quarter general chemistry course. These computer modules were designed to help students connect macroscopic, sub-microscopic, and symbolic representations. Comparison of gain scores on online homework pre and post questions between students taking all “wet” lab curriculum and the module lab curriculum revealed no statistical difference between the module and “wet” lab curriculum. Though the gain scores did not reflect differences in student learning, literature suggests that multimedia environments may be uniquely situated to train students to make connections between levels of representation. To investigate this, discussions between pairs of students were monitored for the extent to which the module labs supported transitions between the three levels of representation, as evidenced by the students’ dialogue. Transitions were then correlated to: 1) level of cognitive processing of the questions in the virtual labs, as measured by their Bloom’s Taxonomy (BT) level, and 2) nature of the visual representations in the questions. Questions with intermediate BT ratings contained the highest frequency of transitions between levels of representation. Transitions within questions at higher levels were more likely to involve symbolic representation than questions at lower levels. Finally, questions with dynamic, interactive visual representations resulted in more transitions than questions with static representations. Our research suggests the level of cognitive processing and type of representations used in a question can cue students to use and translate between particular levels of representation for solving chemistry problems.