The present study aims to define and evaluate usability methodologies, showing where they could be used in the universal design (UD) process. It compares a theoretical prediction against practical examples from across the globe and theorizes on the differences between the two. According to the literature survey, we proposed a chart that could guide whether designers, researchers, etc to use adequate usability methods through the design process cycle. We contacted with some institutions and centers for universal design in the United States, Europe and Japan in order to assess our proposal and assure of its adequacy. The results of this study are the following: 1. The term of usability has two definitions based on the purpose, usability design and usability testing. The former one is concerning the users' requirements and problems. The latter definition is concerning the evaluation of the prototype and its performance. 2. The opinions and the answers of the institutions and the centers on the chart revealed that theory is a good indicator, but practical experience is somewhat different. Some of the contact institutions and centers agree on the chart, but others suggested and added more techniques. The differences in the answers of the contact institutions and centers can be due to many factors, such as, consumers, culture, context, environment, budgets, etc. 3. We need to test our proposal widely, for example by contacting industry and consultative organizations. The intention is to capture data across the spectrum of universal design experience so that it will be useful to see how to teach UD for students and what methods are most useful for industry. This study will be interest for design practitioners, educators, students and decision makers and also to innovators or anyone involved in commissioning design.