Studying Students' Mechanistic Explanations across Undergraduate Chemistry and Biology Courses

Michigan State University, East Lansing MI

Investigators

Abstract

Many STEM students have difficulty in transferring ideas and reasoning from one class to another, for example in transferring knowledge gained in introductory classes into more advanced classes, or across disciplines. This project will examine how undergraduate students use core ideas and mechanistic explanations across introductory courses in three areas: chemistry, cell and molecular biology, and organismal biology. This study will carefully evaluate how students are using what they have learned in a prerequisite course when they take subsequent courses and how this connects with the development of reasoning and understanding. In particular, students will be asked to generate models that explain the problems that they are studying, such as why one patient is cured by an antibiotic while another patient is not. Developing explanations that include mechanisms and models of how and why things happen is an important skill for students to master, and will help them as they enter the scientific or professional workforce. Analysis of these explanations will provide valuable information about: 1) how students apply ideas from chemistry to biology, and 2) factors that help students gain skills in developing high-quality explanations using mechanisms and models. This information will lead to improved teaching that maximizes student application of ideas between introductory science courses and supports the development of reasoning skills needed after students graduate and begin their careers. This project will take advantage of a unique opportunity for researchers from four departments to explore the impact of students' mastery of disciplinary ideas and skills at developing mechanistic explanations on their ability to connect core ideas across courses. The project will use a cross-sectional, comparative analysis of students' mechanistic explanations within and across three sequential introductory courses: chemistry, cell and molecular biology, and organismal biology. In each course, students will use a combination of diagrams and writing to explain how and why a series of three related phenomena occur. The mechanistic explanations will be analyzed for cause-and-effect relationships between underlying factors needed to provide a scientifically sound explanation of the phenomena. These analyses will determine: 1) if students in undergraduate STEM courses use relevant core disciplinary ideas to explain how and why phenomena occur; 2) how explanation sophistication varies at different points in the curriculum; 3) the impact of mechanistic explanation sophistication in one discipline on the use of related disciplinary core ideas to explain phenomena in other disciplines; and 4) relationships between demographic and academic variables, explanation sophistication, and success on course exams. Findings from this study will advance research on the nature of and connections between students' disciplinary core ideas and explanatory practices beyond single courses by looking across courses. The assessment tools and analysis techniques used in this study will provide a foundation for further research in this understudied area including future longitudinal studies and research on the impact of instruction on students' abilities to construct sophisticated explanations. Insights from this work will also be used to develop an evidence-based instruction framework. The framework will provide a progression of learning objectives across introductory chemistry and biology courses indicating what needs to be mastered in each course to produce sophisticated explanations in subsequent courses. In addition, the framework will document common ways students use vocabulary to make connections between the courses as well as ways how differences in vocabulary between courses prevents transfer of ideas across courses. This framework will serve as a guide for future evidence-based STEM course and curriculum remodeling efforts geared toward producing well-prepared citizens and scientists.