Iteration in Usabilty Testing: Instructive Interfaces of a Dietary Plan in Diabetics

The goal of usability testing is to make design decisions based on objective data and user-centered criteria. Iteration in usability testing is key to identify the design decisions that hinder the interaction between users and interfaces, additionally validates the design elements that enhance it. When the usability testing is applied to systems or interfaces related to users’ health issues, such as diabetes, benefits in both in the interaction as well in user welfare are obtained. Diabetes complications can be diminished through the metabolic control of the patient, which is achieved through the implementation of a dietary plan. Two usability assessments were carried out during the interface development, this study presents the second iteration of the assessment of the interface redesign based on the results of the first evaluation, the feedback from the participants and the application of the ergonomic guidelines. Three dimensions of usability were evaluated: satisfaction, efficiency and effectiveness. Both interfaces showed similar results in usability. The use of color was identified as a design element to be assessed in an isolated manner. The iterative assessment allowed to improve the proposed guidelines for the design of instructional interfaces and when applied in the interface design process, results in a positive effect on its usability. In addition, the recommendations made by the users of the first test were validated through the iterative testing, making this a user centered process.