Investigating the role of multiple categorization tasks in a curriculum designed around mechanistic patterns and principles

The goal of the present work is to extend an online reaction categorization task as a research instrument to a formative assessment tool of students' knowledge organization for organic chemistry reactions. Herein, we report our findings from administering the task with undergraduate students in Organic Chemistry II, at a large, research intensive Canadian university, including the relationship between instrument and exam scores. The online categorization task uses 25 reaction cards that participants were asked to sort first into categories of their choosing (i.e., an open sort) then into the mechanistic categories defined in a Patterns of Mechanisms curriculum (i.e., a closed sort). We observed a small, significant correlation between how learners chose to organize their knowledge (i.e., open sort) and their cued ability (i.e., match with expert sort) at the beginning of the Organic Chemistry II course (N = 65, r = 0.28, p = 0.026). We conducted a correlation analysis between students' scores on the open and closed sort tasks and academic achievement. We found a strong relationship between the scores in the online categorization tasks and Organic Chemistry II exams, especially from the closed sort tasks (N = 43, r = 0.70, p = 0.000). To date, no other discipline specific card-sort tasks have shown such a strong correlation with final assessment grades. We also found an increasing relationship between students' choice and ability over time as students developed their expertise in the domain. This work also added evidence to the validity and reliability of the organic card-sort instrument, through multiple measures. Educators and students could use the card sort task as a self-assessment measure and as part of classroom activities related to mechanistic analysis. Future work is needed to investigate how card sort tasks of this type are connected with expertise in other settings.