No abstract

Past work has demonstrated that language comprehension ability correlates with general chemistry course performance with medium effect sizes. We demonstrate here that language comprehension’s strong cognitive grounding can be used to inform effective and equitable pedagogies, namely, instructional interventions that differentially aid low-skilled language comprehenders. We report the design, implementation, and assessment of such an intervention strategy. Guided by two models of comprehension, we predicted that a multiple pre-testing strategy would differentially aid low-skilled comprehenders in a general chemistry class. We also explored the effect of two question types (multiple choice and elaborative interrogation) on this intervention strategy. A within-subjects, learning-goals driven design was used to build the intervention into two semesters of the course; data generated by this approach were analyzed with hierarchical linear models. We found that the achievement gap between low- and high-skilled comprehenders was partially abated by repeated testing prior to course examinations. We also found that the differential benefits of repeated testing could be accounted for entirely by multiple-choice questions, while elaborative interrogation questions had a statistically significant, but negative, impact. The implication of this work for all levels of chemistry teaching is clear: testing can be used to enhance (not just to assess) student learning, and this act affects different groups of students in different ways.

Prior chemistry education research has demonstrated a relationship between student reading skill and general chemistry course performance. In addition to student characteristics, however, the qualities of the learning materials with which students interact also impact student learning. For example, low-knowledge students benefit from texts that explicitly state relationships between ideas, namely, those that possess high cohesion. Such texts limit the number of inferences a student must draw: a practice crucial for students lacking the requisite prior knowledge to fill in conceptual gaps. In this study, five best-selling general chemistry texts were analyzed using Coh-Metrix, a tool created to measure the linguistic characteristics of discourse and text. Our results constitute a survey of five measures of text difficulty: narrativity, syntactic simplicity, word concreteness, referential cohesion, and deep cohesion. Statistically significant differences were found when comparing the cohesion of the chemistry texts. Therefore, some texts may be more optimal for low-knowledge students than the others. In addition, four of the five texts had an optimal distribution of cohesion. This work also demonstrates the utility of Coh-Metrix as a tool that instructors can use to assess the appropriateness of learning materials for students based on their reading skill and prior chemistry knowledge.