Qualitative usability evaluation is usually included within the Evaluation Stage in Usability Engineering through a Qualitative Usability Testing process QUT. This QUT process includes the application of methods that have been defined focusing on the evaluation of a particular interactive system, becoming highly expensive when a context of use has to be evaluated (by analyzing a large number of interfaces belonging to that context) in order to detect common usability problems from a qualitative viewpoint. This paper presents the QUT CKDD methodology which incorporate techniques from Knowledge Discovery in Databases, extending the existing QUT process in order to solve the above situation. To illustrate the QUT CKDD methodology, an experimentation related to a particular Latin-American context of use is also discussed.