Improving STEM Courses By Focusing On Threshold Concepts: Deciding What Content To Teach

Background:  Over the past years Science has published articles advocating for changing how we teach in order to better engage students.  Equally important to consider is what concepts to teach. Threshold concepts (TCs) as a theoretical framework was proposed by Meyer and Land as a means to improve instruction by focusing on those concepts that would move students from novice to expert understanding of the discipline. TCs are concepts that, when mastered, represent a transformed understanding of a discipline, without which the learner cannot progress.  In this study we investigated the question: What are potential TCs for biochemistry? Our ultimate goal is to design instruction and assessment tools for a set of TCs in biochemistry. Methods:  The TC literature describes qualitative research methods to uncover candidate TCs. Our research therefore included three faculty workshops and several rounds of student interviews. The process involved over 70 faculty members and over 50 undergraduate students at five diverse institutions. The student focus groups were conducted using a semi-structured interview protocol. The interviews were transcribed and thematic analysis performed.  We used an iterative process of analyzing the transcripts from student interviews and notes from faculty workshops to define and prioritize five concepts on which to focus future development of instructional materials.  One classroom activity was developed at a subsequent faculty workshop and piloted with students in Fall 2014 at two institutions. Results:  The five high priority TCs are steady state, biochemical pathway dynamics and regulation, the physical basis of interactions, thermodynamics of macromolecular structure formation, and free energy.  Experts deemed these concepts important for understanding biochemistry and students exhibited limited understanding of the concepts. Therefore, these particular TCs are ideal candidates for curricular development and will be used to develop instructional and assessment tools for undergraduate biochemistry.  Piloting of a classroom activity provided preliminary evidence of efficacy to improve student understanding of the physical basis of interactions. Conclusions:  Our process to identify TCs can be used by others interested in identifying TCs for their discipline. We are currently designing instructional materials and assessment instruments that focus on the identified TCs. We were surprised that the physical basis of interactions remains a problem for students enrolled in biochemistry.