This article presents a methodological approach of evaluation of the usability in educational environments ME-UsitE, an analysis of the necessity to implement a tool of evaluation and measurement of the usability to support the methodology, that contributes to the detection of problems and failures of usability from the perspective of the user of educative websites in a real work environment. Taking into account that the websites are designed and implemented for a domain and audience in particular, it is important to consider factors like these for the implementation of a tool that allows not only to carry out the evaluation process but also to support the analysis of the gathered data. Thus, the obtained results may allow us to establish policies for the improvement of the usability of the site, when providing a score that determines whether the level of usability offered covers the requirements for the proposed audience and the profile of the participant user in the evaluation.