P341: Making predictions about chemical reactivity: Assumptions and heuristics

Author: Vicente Talanquer, University of Arizona, USA

Co-Author: Jenine Maeyer, University of Arizona, USA

Date: 8/4/14

Time: 2:05 PM2:25 PM

Room: MAN 107

Related Symposium: S31

Diverse implicit cognitive elements seem to support but also constrain reasoning in different domains. Many of these cognitive constraints can be thought of as either implicit assumptions about the nature of things or reasoning heuristics for decision-making. In this study we applied this framework to investigate college students’ understanding of structure-property relationships in the context of chemical reactivity. The ability to understand and apply structure-property relationships to explain the behavior of physical, chemical, and biological systems is a core competence that many science and engineering majors are expected to develop. Core findings were derived from semi-structured interviews based on a ranking task. Study participants relied on intuitive, spurious, and valid assumptions about the nature of chemical entities in building their responses. In particular, many of students appeared to conceive chemical reactions as macroscopic reassembling processes thought to be more favored the easier it seemed to break reactants apart or put products together. Students also expressed spurious chemical assumptions based on the misinterpretation and overgeneralization of chemical ideas. Reasoning heuristics for decision-making also played a significant role in the construction of answers to ranking questions. Specifically, interviewees demonstrated strong over-reliance on variable reduction strategies and recognition memory in their reasoning. Our findings reveal the need for educational approaches that more effectively affect the conceptual sophistication and depth of reasoning about structure-property relationships of college students. Our research framework provides a productive approach for the analysis of student reasoning in scientific domains.

P216: What we see may not be what is!

Author: Vicente Talanquer, University of Arizona, USA

Co-Author:

Date: 8/4/14

Time: 9:35 AM9:55 AM

Room: LOH 164

Related Symposium: S25

Students in our chemistry classes often generate shallow responses to our questions and problems. They fail to recognize relevant cues in making judgments and decisions about the properties of chemical substances and processes. As a result, they make hasty generalizations that frequently lead them astray. Results from research in the psychology of decision-making can help us better understand how our students approach chemistry tasks under conditions of limited knowledge, time, or motivation. In this contribution, I describe research in chemistry education that suggests that students’ answers to the questions and problems we pose may be less indicative of what they actually know or believe, and more revealing of reasoning strategies that students apply to generate quick answers under conditions of uncertainty.

P152: Developing a learning progression on chemical synthesis

Author: Melissa Weinrich, University of Arizona, USA

Co-Author: Vicente Talanquer, University of Arizona, USA

Date: 8/4/14

Time: 9:55 AM10:15 AM

Room: LTT 103

Related Symposium: S13

In order to support the development of learning progressions about central ideas and practices in chemistry, we need detailed analyses of the implicit assumptions and reasoning strategies that guide students’ thinking at different educational levels. We have used a qualitative research approach based on individual interviews with first-semester general chemistry (n=16), second-semester organic (n=15), advanced undergraduates (n=9), first year graduate students (n=14), and PhD candidates (n=16) to better characterize the evolution of students’ conceptual sophistication and modes of reasoning about chemical synthesis. Our results reveal a great variability in the cognitive resources and strategies used by students to make decisions, particularly at intermediate levels of expertise. Nevertheless, our data analysis has allowed us to identify common modes of reasoning and assumptions that seem to guide students thinking at different levels in their training. Our results should facilitate the development of learning progressions that help improve chemistry instruction, curriculum, and assessment.

P153: Exploring college and graduate students’ reasoning about chemical reactions

Author: Fan Yan, University of Arizona, USA

Co-Author: Vicente Talanquer, University of Arizona, USA

Date: 8/4/14

Time: 10:15 AM10:35 AM

Room: LTT 103

Related Symposium: S13

Understanding chemical reactions is crucial in learning chemistry at all educational levels. Nevertheless, research in science education has revealed that many students struggle to understand chemical processes. Improving teaching and learning about chemical reactions demands that we develop a clearer understanding of student reasoning in this area and of how this reasoning evolves with training in the discipline. Our study was designed to a) explore the types of reasoning about chemical reactions expressed by students at different educational levels, b) identify common reasoning patterns, c) identify and characterize major constraints in student reasoning, and d) characterize potential learning pathways in the understanding of such processes. Main findings indicate that although significant progress is observed in student reasoning in some areas, major conceptual difficulties seem to persist even at the more advanced educational levels. The results of our study are relevant to educators interested in learning progressions, assessment, and conceptual development.