“Al Badre's book is about an everlasting truth--a truth that many people, many companies, many organizations have learned the hard way. That is, when designing technological systems for people to use, one must take into account the characteristics of the users, and the nature of the task, and the knowledge, experience, biases, strengths, and weaknesses that the users bring to the task. In the case at hand, the task is using the World Wide Web.”, James D. Foley, cited by informIT, retrieved 16:51, 18 November 2010 (CET))
The essence of a web usability structure, is according to Badre (2002:chapter 2):
See also: usability (more general) web accessibility, HCI (human-computer interaction the most important academic displine dealing with usability).
Do not believe that usability testing is asking for opinions, e.g. with questionnaires, although it is sometimes done for various reasons, i.e. to obtain subjective impressions of a larger audience or also to test satisfaction. Usability testing may include several kinds of activities, but the most important is giving users tasks to do and to observer how they do.
See Design and usability methods and techniques and if you are interested in survey see Usability and user experience surveys
See also usability and User interaction and user interface design