Many organic chemistry learners have difficulty ranking the relative strengths of acids and bases using conceptual understanding. This skill is important for correctly predicting chemical reactivity and drawing reasonable reaction mechanisms. Identifying misconceptions during learning can help educators improve curriculum and instruction, and help students guide their studying. Previous studies have recognized several mental models, or problem-solving approaches, that contribute to acid-base misconceptions; however, these models are insufficient at pinpointing the specific sources of knowledge gaps underlying the students’ mistakes. To this end, we developed a 15-item, multi-tiered and adaptive multiple-choice concept test using misconceptions we identified with think-aloud protocols. The test identifies how students compare pairs of acids and drills down to uncover their specific ways of thinking about electronegativity, atom size, resonance, hybridization, induction, and aromaticity in relation to acid strength and base stability.<br/><br/>This presentation will include an overview of the development process and the results of our validity and reliability studies, including expert validation for clarity and scientific correctness. We will also describe our process for providing personalized feedback based on how students respond to the test items. Preliminary evidence from general chemistry and organic chemistry courses suggests that this test is useful for identifying specific aspects of student thinking. We anticipate that this test will allow instructors to analyze whether students fully understand and correctly apply the factors involved in determining acid strength.

Validity and reliability of a concept test to measure students’ abilities to qualitatively rank acid and base strength

2019 Spring National Meeting

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