Rotondi AJ, Spring MR, Hanusa BH, Eack SM, Haas GL. (2017). Designing eHealth applications to reduce cognitive effort for persons with severe mental illness: Page complexity, navigation simplicity, and comprehensibility. JMIR Human Factors. 4(1): e1. doi: 10.2196/humanfactors.6221
The Flat Explicit Design Model (FEDM) is a framework that guides the development of web-based resources for people with severe mental illness (SMI). This study evaluated a refined version of the FEDM, which organizes 19 variables that are important to website usability among people with SMI into three larger dimensions: page complexity (e.g. number of navigation areas, display distractions, reading ease), navigation simplicity (e.g. use of a toolbar, hyperlink labels, introductory content location), and comprehensibility (e.g. number of words, memory aids, reading level). Researchers recruited 38 participants with schizophrenia to evaluate five websites about schizophrenia. Websites were scored on their complexity according to the FEDM. Participants were asked to complete tasks to evaluate how easily they could identify the information available and how long it took them to find specific information. Participants also rated the overall usability of each website. Researchers compared participants’ evaluations of each website to that website’s complexity based on the FEDM to determine the validity of the FEDM. Eleven variables, from all three dimensions of the FEDM, were related to all four of the evaluation outcomes. Complexity and navigational simplicity were related to ability to find information, time needed to find information, and ease of use scores. Describing information presented on a website was related to navigational simplicity and comprehensibility.