Using multiple representations to enhance understanding of molecular structure: a blended learning activity

Abstract

One of the challenges of teaching an introductory chemistry course is to balance the requirement of covering a prescribed set of concepts and skills with providing opportunities for students to spend time with, and apply, a single concept. In this chemistry course, students encounter an array of molecular representations including line drawings, condensed structures, ball and sticks and three dimensional space filled molecules. They must quickly become fluent in translating between these representations and in a lecture setting are likely to acquire misconceptions. To address these issues, a blended learning workshop was developed to present active learning opportunities for students in the application and extension of their understanding of molecular structure. An integrative approach was adopted by using the context of fats in the diet to demonstrate the relevance of the chemistry concepts to the student’s daily lives. This involved the adaptation of a successful ChemConnections initiative (http://mc2.cchem.berkeley.edu/). Students were guided through inquiry activities involving online resources (Jmol), hands-on molecular model kits (Molymod) and a graphics application on individual tablet PCs where they drew molecular structures. Student learning gains and metacognitive processing were measured via three strategies incorporating the unique facilities of the teaching space. The availability of individual tablet computers enabled collection of student representations of a line structure prior to commencement of the workshop. As part of the assessment of the exercise, students were invited to submit brief reflections (via personal blogs managed through Blackboard). Students identified multiple themes regarding the aspect of the workshop that had impacted on their learning (working as groups, molecular models and the high technology facilities). Gains in conceptual understanding were explored through two post-workshop assessment tasks. A related problem was placed in PASS (Peer Assisted Study Sessions) where students worked in peer groups without instructor input, and a short answer question was included in the summative exam for the course. Students reported high confidence levels in their ability to recognise organic structures as a result of the activities encountered during the workshop. A mixed methods approach was adopted for the evaluation of the learning experience including pre- and post-tests conducted at each workshop, focus group interviews and feedback from students (postworkshop reflections, a problem set in a pseudotutorial environment and summative exam question). Data gathered has been evaluated through quantitative and qualitative analysis (SPSS and NVivo).