Identifying threshold concepts in learning nanoscience by using concept maps and students' responses to an open-ended interview

This study explores students understanding of key concepts in nanoscience with the intention of identifying a potential threshold concept in the field through the analysis of student concept maps and explanatory interviews. The analysis of students’ maps indicates conceptual development and learning difficulties in learning size–dependent property change at the Nano-scale. In addition, it identifies potential threshold concepts in the study and understanding of nanoscale science from the students’ perspective. It also indicates the importance of previous learning in science to integrate isolated concepts and to help students achieve a deeper understanding of key phenomena at the nanoscale. Introduction and Rationale Since Feynman (1960) invited us to the “room at the bottom”, nanoscience and technology has not only attracted considerable interest from scientists and engineers but also from the general public. While it has grown as a new, potentially rich field in science, substantial attention has yet to be given on research about its educational perspectives. Recent studies (Stevens, S. et. al. 2007) with scientists, engineers and learning scientists, have identified a number of potential ‘big ideas’ or key concepts central to the understanding of nanoscale science and technology. To the end, this study is a preliminary exploration of students understanding of a number of those key concepts with the intention of identifying a potential threshold concept in the field. Meyer and Land (2003, 2006) describe the term, threshold concept as a conceptual gateway representing ‘a transformed way of understanding, or interpreting, or viewing something without which the learner cannot progress’. Threshold concepts have also been characterized as being transformative, integrative, probably irreversible, potentially troublesome, and often boundary makers (Meyer and Land, 2003). The troublesomeness of knowledge here refers to a concept being conceptually difficult, meaningless, inert, alien or implicit (Perkins, 1999 & 2006). Traditionally key concepts or big ideas in a discipline (including potential threshold concepts) have been identified through research methods aimed at developing a consensus of expert opinion (Stevens, S. et. al. 2007). Similarly, concepts which are troublesome with respect to student understanding have often been identified by experts ‘through professional reflection on the nature of the subject as a conceptual entity’ (Davies 2006). In so far as these methods draw upon expertise to identify problems for student understanding, such methods might be referred to as ‘top-down’ approaches. On the other hand, ‘bottom up’ approaches focus on identifying troublesome concepts through research with students, themselves. Such approaches identify both the variation in the ways in which students experience or understand a concept and the key dimensions of variation which might constitute the troublesomeness of the concept such as the aspects of variation revealed in phenomenographic studies (Marton & Booth 1997). This study primarily focuses on the less frequently taken ‘bottom up’ approach, although it is done against the background of a ‘top down’ perspective of a faculty expert. For the purposes of this study, the experts concept map is not used here as a means of comparison with student concept-maps but rather as a way of identifying the key concepts in the specific area.