Alex T. Kararo

Students often struggle to make interdisciplinary connections and cite a lack of opportunity to make such connections. To address this issue, we are developing activities aligned with the framework of three-dimensional learning that provide students with opportunities to make connections between chemistry concepts and biological phenomena. Here, we focus on an activity that asks students to incorporate the concept of entropy in explaining the biological phenomenon of osmosis across a cell membrane. This activity was administered in both introductory cell and molecular biology and second-semester general chemistry courses. We found that after completing carefully scaffolded questions within the activity, students were better able to correctly use the concept of entropy in explaining osmosis than they were before the scaffolding questions. Additionally, we found that students’ course history appeared to impact their explanations of this phenomenon in that students who had taken second-semester general chemistry (i.e., the semester in which entropy is discussed for these students) provided more sophisticated responses and were less likely to include scientifically inaccurate ideas than their peers who had not taken second-semester general chemistry.

The ability to predict macroscopic properties using a compound's chemical structure is an essential idea for chemistry as well as other disciplines such as biology. In this study we investigate how different levels of interventions impact the components of students’ explanations (claims, evidence, and reasoning) of structure–property relationships, particularly related to boiling point trends. These interventions, aligned with Three-Dimensional Learning (3DL), were investigated with four different cohorts of students: Cohort 1 – a control group of students enrolled in an active learning general chemistry course; Cohort 2 – students enrolled in the same active learning general chemistry course but given Intervention 1 (a 3DL worksheet administered during class time); Cohort 3 – students enrolled in the same active learning general chemistry course but given Intervention 1 and Intervention 2 (a 3DL course exam question administered after instruction); and Cohort 4 – a reference group of students enrolled in a transformed active learning general chemistry curriculum in which 3DL is an essential feature and includes Intervention 1 and Intervention 2 as part of the curriculum. We found that Cohort 2 students (with the 3DL worksheet intervention) were more likely than the control group (Cohort 1) to correctly predict the compound with a higher boiling point as well as incorporate ideas of strength of intermolecular forces into their explanations of boiling point differences. When a 3DL exam question was given as a follow up to the 3DL worksheet, students in Cohort 3 were more likely than Cohorts 1 and 2 to correctly identify the claim. Further comparison showed that Cohort 4 (transformed general chemistry curriculum) were more likely than Cohorts 1–3 to also include the ideas of energy needed to overcome stronger forces for a more sophisticated explanation (50% of Cohort 4 students compared to 17–33% for Cohorts 1–3). In addition, 80% of Cohort 4 students were able to construct a correct representation of hydrogen bonding as a non-covalent interaction compared to 13–57% for the other three cohorts.

Students tend to think of their science courses as isolated and unrelated to each other, making it difficult for them to see connections across disciplines. In addition, many existing science assessments target rote memorization and algorithmic problem‐solving skills. Here, we describe the development, implementation, and evaluation of an activity aimed to help students integrate knowledge across introductory chemistry and biology courses. The activity design and evaluation of students' responses were guided by the Framework for K‐12 Science Education as the understanding of core ideas and crosscutting concepts and the development of scientific practices are essential for students at all levels. In this activity, students are asked to use their understanding of noncovalent interactions to explain (a) why the boiling point differs for two pure substances (chemistry phenomenon) and (b) why temperature and base pair composition affects the stability of DNA (biological phenomenon). The activity was implemented at two different institutions (N = 441) in both introductory chemistry and biology courses. Students' overall performance suggests that they can provide sophisticated responses that incorporate their understanding of noncovalent interactions and energy to explain the chemistry phenomenon, but have difficulties integrating the same knowledge to explain the biological phenomenon. Our findings reinforce the notion that students should be provided with opportunities in the classroom to purposefully practice and support the use and integration of knowledge from multiple disciplines. Students' evaluations of the activity indicated that they found it to be interesting and helpful for making connections across disciplines.

The relationship between chemical structure and physical and chemical properties is essential to chemistry. Studies have shown that students have difficulty using structural representations to predict properties, which is not surprising because of the sequence of inferences that are required for sense-making. However, obtaining a nuanced model of students’ understanding depends on how information is elicited. This study investigated how the phrasing of the question prompt may elicit students’ understanding of structure–property relationships. Students were given a two-part assessment: (1) four multiple-choice questions assessing students’ self-reported abilities to predict structure–property relationships, and (2) three questions requiring students to predict, argue, and explain a boiling point trend. Two groups of students were selected to determine the sensitivity of the instrument (one with less explicit instruction of structure–property relationships and one with more explicit instruction). We found that Part I of the assessment was able to differentiate between these two groups of students. The group with more explicit instruction was further analyzed to determine how their prediction on a boiling point task connected to their arguments and explanations of the phenomenon. Even though 64% of students answered the boiling point ranking task correctly, the students typically provided less complete arguments as to why that structure had a higher boiling point. However, after scaffolding (i.e., providing relevant information for the phenomenon) and asking for an explanation, students’ responses began to include a much more mechanistic understanding, suggesting that having students provide explanations instead of constructing an argument would display their reasoning at a deeper level.