Models as feedback: Developing representational competence in chemistry.

Abstract

Spatial information in science is often expressed through representations such as diagrams and models. Learning the strengths and limitations of these representations and how to relate them are important aspects of developing scientific understanding, referred to as representational competence. Diagram translation is particularly challenging for students in organic chemistry, and although concrete models greatly help in solving diagram translation problems, most students do not use models spontaneously. In 2 experiments, we examined the effectiveness of instructional interventions for teaching diagram translation using models. In Experiment 1. students drew diagrams and checked their accuracy by attempting to match concrete models to their solutions (model-based feedback). The instruction helped students in the experimental group to identify their mistakes, understand the usefulness of concrete models, and led to large improvements in performance, compared with a control group. To examine whether feedback, the opportunity to match models, or both was the critical aspect of the intervention, in Experiment 2, 1 group was provided only verbal feedback (by a tutor) and another group matched diagrams and concrete models, but not in the context of receiving an evaluation of their pretest performance. Feedback alone did not improve performance relative to a control group, but the oppor tunity to match models and diagrams improved performance relative to control. The results indicate that using models as feedback is an effective way of training representational competence in the domain of organic chemistry and more generally in science, technology, engineering, and mathematics disciplines.Spatial information, such as shape, size, structure, and motion, is particularly important in the natural sciences, and certain branches of science are devoted to studying spatial properties. For example, anatomy is the study of the structure of living things, geology is the science of the structure of the earth, and stereo chemistry is the study of the structure of compounds. Understand ing spatial information is particularly challenging when the rele vant structures are not directly observable, for example, because they occur at a scale of space that is not visible (e.g., molecules) or are internal to some three-dimensional (3-D) structure that we typically only see from the outside (e.g., internal anatomy). In these cases, spatial information is represented most directly through spatial representations such as diagrams, concrete and virtual models, and animations; it is also represented using nonspatial representations such as text, symbols, and formulae.Scientists are facile in using a range of different representations of spatial phenomena that vary in their dimensionality (e.g., twodimensional [2-D] vs. 3-D), abstraction (e.g., diagrams vs. equa tions), and spatial perspective (e.g., orthographic vs. isometric projections, cross-sections) to represent, reason, and communicate about different spatial phenomena (Ainsworth, 2006;Kozm...

Students’ representational competence with drawing technology across two domains of science

“…Research has indicated effective instructional methods to promote students’ representational competence in science, including use of concrete models (Padalkar & Hegarty, ; Stieff et al., ; Stull et al., ) or virtual models (Stull & Hegarty, ), and engaging students in construction, interpretation, or evaluation of representations (Chang et al., ; Nichols, Gillies, & Kleiss, ; Prain & Tytler, ; Zhang & Linn, ). Although the current study did not investigate how to promote students’ representational competence by interventions, the results provide insights into the nature of students’ representational competence of science including the central role of using multiple representations.…”

“…Investigations of students’ representational competence in science have advanced the understanding in this field with the following findings. First, aspects of students’ representational competence in science can be improved by interventions that use concrete models (Padalkar & Hegarty, ; Stieff, Scopelitis, Lira, & Desutter, ; Stull, Gainer, Padalkar, & Hegarty, ) or virtual models (Stull & Hegarty, ), and by interventions that engage students in representational practices such as construction, interpretation, or evaluation of representations (Chang, Quintana, & Krajcik, ; Nichols, Gillies, & Hedberg, ; Prain & Tytler, ; Zhang & Linn, ).…”

Effects of interface and spatial ability on manipulation of virtual models in a STEM domain

“…By using 3D models rather than 2D diagrams for depicting target orientations, the task in Experiment 2 focused more on the virtual manipulation itself and eliminated the potential confound of participants' ability to interpret diagrams. Interpreting molecular diagrams has been shown to be difficult even for organic chemistry students Padalkar & Hegarty, 2015), so using 3D target models allowed for a more focused examination of virtual object manipulation performance, independent of participants' ability to interpret organic chemistry diagrams as in Experiment 1. Matching the orientation of two 3D objects is more consistent with previously studied tasks, as comparing two Figure 4: In Experiment 2, participants aligned the below model to match the orientation of 3D models.…”

Situating space: using a discipline-focused lens to examine spatial thinking skills

“…For instance, mental rotation is critical to problem-solving in chemistry (e.g., Harle & Towns, 2011;Stieff, 2007) and surgery (Hegarty et al, 2007), as well as mathematics (e.g., Gilligan, Hodgkiss, Thomas, & Farran, 2017;Lombardi, Casey, Pezaris, Shadmehr, & Jong, 2019;Lowrie & Logan, 2018). On the other hand, field-relevant spatial skills that involve specific tools of representation reflect disciplinary core ideas that are important for and specific to reasoning and understanding within the STEM discipline of interest, such as skills for interpreting 2D diagrams in chemistry (e.g., Padalkar & Hegarty, 2015;Stieff, 2011;Stull & Hegarty, 2016) and skills for interpreting topographic maps in geology (e.g., Atit et al, 2016;Chang et al, 1985;Eley, 1983). As outlined by the National Research Council (2012a) framework, both crosscutting concepts (e.g., fundamental spatial skills) and core disciplinary ideas (e.g., field-relevant spatial skills) are needed for meaningful learning within the STEM disciplines.…”

“…Because spatial thinking at the expert level in STEM domains is influenced by the expert's domain knowledge and is context-dependent, students who find completing fundamental spatial tasks difficult may still succeed in STEM with the appropriate scaffolds and supports. For example, the use of ball and stick models in organic chemistry facilitates student performance on diagram translation problems (Padalkar & Hegarty, 2015), and interactive animations in structural geology bolsters student understanding of 3D geologic structures represented in topographic maps (Reynolds et al, 2005). Thus, future research should focus on identifying discipline-specific spatial reasoning measures, as well as scaffolds and tools that support students' spatial problem-solving for each STEM field.…”