Sachel M. Villafañe

College students’ attitudes toward chemistry, conceptual knowledge and achievement: structural equation model analysis

Students’ success in introductory college-level chemistry courses is important for them to continue to more advanced science courses and to progress toward science-related careers. Previous studies indicate that both cognitive and non-cognitive variables are relevant for student success. In this study, Structural Equation Modeling (SEM) was used to predict students’ achievement in chemistry from both cognitive (math ability, prior conceptual knowledge in chemistry) and non-cognitive (attitude toward chemistry) measures. The purpose of this study is to investigate which of three alternative SEM models best represents the relationships among these variables and achievement in chemistry, and what proportion of variance in chemistry achievement can be explained. Results provide support for using a SEM model with all three predictors, with 69% of the variance in chemistry achievement explained. Both prior conceptual knowledge and attitude toward chemistry contribute a significant unique portion to the prediction of chemistry achievement when controlling for math ability. The results suggest that instructors can improve students’ achievement in chemistry not only by focusing on helping them to build conceptual knowledge, but also by fostering their positive attitude toward chemistry. This study also has implications for SEM researchers, both to further replicate the study in other contexts, and to add other potentially relevant predictors. Instrument developers may also use the modeling strategy as a springboard for optimizing assessment tools.

Uncovering students' incorrect ideas about foundational concepts for biochemistry

This paper presents preliminary data on how an assessment instrument with a unique structure can be used to identify common incorrect ideas from prior coursework at the beginning of a biochemistry course, and to determine whether these ideas have changed by the end of the course. The twenty-one multiple-choice items address seven different concepts, with a parallel structure for distractors across each set of items to capture consistent incorrect responses. For the current study, the instrument was administered as a pre-test and post-test in majors level biochemistry courses, and the results from two different groups are presented. These results indicated that students performed better on the post-test, resulting in positive mean gain scores for each concept. The structure of the instrument allows data analysis that helped uncover persistent incorrect ideas for some of the concepts, including bond energy and protein alpha helix structure, even after a semester of instruction in biochemistry. The persistent incorrect idea for the protein alpha helix structure uncovered by this assessment has not been reported before in the literature. These results confirm the need to use a robust diagnostic instrument to assess students’ understanding of basic concepts at the beginning of the semester, but also stress the need to assess students near the end of the course to gain insight on the effectiveness of instruction. Since each group of students is different, biochemistry instructors are encouraged to use the instrument to identify problems with their own students’ incoming ideas rather than rely on published results to inform instruction. In addition to providing assistance for instructors of biochemistry in planning targeted instructional interventions, we anticipate that data collected from this instrument can also be used to identify potential modifications for prerequisite courses.

Probing and improving student's understanding of protein α‐helix structure using targeted assessment and classroom interventions in collaboration with a faculty community of practice

The increasing availability of concept inventories and other assessment tools in the molecular life sciences provides instructors with myriad avenues to probe student understanding. For example, although molecular visualization is central to the study of biochemistry, a growing body of evidence suggests that students have substantial limitations in their ability to recognize and interpret basic features of biological macromolecules. In this study, a pre/posttest administered to students at diverse institutions nationwide revealed a robust incorrect idea about the location of the amino acid side chains in the protein α‐helix structure. Because this incorrect idea was present even after a semester of biochemistry instruction at a range of institutions, an intervention was necessary. A community of expert biochemistry instructors collaborated to design two active learning classroom activities that systematically examine α‐helix structure and function. Several participating faculty used one or both of the activities in their classrooms and some improvement of student understanding of this concept was observed. This study provides a model of how a community of instructors can work together using assessment data to inform targeted changes in instruction with the goal of improving student understanding of fundamental concepts.