Examining the relationship between 2D diagrammatic conventions and students' success on representational translation tasks in organic chemistry

摘要

Two-dimensional (2D) diagrams are essential in chemistry for conveying and communicating key knowledge about disciplinary phenomena. While experts are adept at identifying, interpreting, and manipulating these representations, novices often are not. Ongoing research efforts in the field suggest that students' effective use of concrete and virtual manipulatives can support their development of representational competence in the domain. However, as these affordances are not always present within the learning environment, it is imperative that educators evaluate the influence diagrammatic conventions have on student success in the discipline, specifically on tasks requiring translation between two, 2D diagrams. In this study, we adopt a quantitative approach to examine students' accuracy at translating between Dasha€“Wedge and Newman projections, as well as Dasha€“Wedge and Fischer projections when the conventions of each of these representations are varied (e.g., staggered vs. eclipsed conformation of the Dasha€“Wedge diagram, rotation of the Newman Projection). Results indicate two important findings. First, students perform significantly better on Dasha€“Wedge to Newman tasks when the Newman projection has undergone no rotation (i.e., when the two representations are exact conformers of one another) compared to simple or complex rotations. Second, students' degree of success on Dasha€“Wedge to Fischer translation tasks is directly related to the conformation and spatial arrangement of substituents on the Dasha€“Wedge diagram, with poorer performance noted on tasks in which the visuospatial conformation of the Dasha€“Wedge representation is both staggered and inconsistent with the participants' preferred viewing perspective. Together, these data reaffirm the need to explore in greater detail how 2D diagrammatic conventions impact novices' ability to successfully translate between representations in organic chemistry.