Using Graphics to Improve Understanding of Conceptual Models

Abstract

Making Entity-Relationship diagrams easier to understand for novices has been a topic of previous research. This study provides experimental evidence that suggests using small representative graphics (iconic graphics) to replace standard entity boxes in an ER diagram can have a positive effect on domain understanding for novice users. Cognitive Load Theory and the Cognitive Theory of Multimedia Learning are used to hypothesize that iconic graphics reduce extraneous cognitive load of model viewers leading to more complete mental models and consequently improved understanding. Domain understanding was measured using comprehension and transfer (problem solving) tasks. Results confirm the main hypothesis. In addition, iconic graphics were found to be less effective in improving domain understanding with English as second language (ESL) participants. ESL results are shown to be consistent with predictions based on the Cognitive Load Theory. The importance of this work for systems analysts and designers comes from two considerations. First, the use of iconic graphics seems to reduce the extraneous cognitive load associated with these complex systems. Secondly, the reduction in extraneous load enables users to apply more germane load which relates directly with levels of domain understanding. Thus iconic graphics may provide a simple tool that facilitates better understanding of ER diagrams and the data structure for proposed information systems.