– As the computers are included in our daily lives more and more, the importance of comfortable and easy usage of interfaces in computer media has been increasing day by day. There are different approaches which are used to evaluate the usability of these interfaces. The aim of this study is to investigate the effect of the data obtained by applying the user centered and model based approaches on usability in terms of the solution of usability problems that the web interface has. Within this context, with the help of 12 academicians who work at Gaziosmanpaşa University Faculty of Medicine, the user centered approach was conducted on “Faculty of Medicine Assessment and Evaluation” system. The data obtained from CogTool was used for Model Based approach. As a result of this study, it was concluded that both approaches increased the usability, but when they were used separately, they were incompetent to diagnose some of the usability problems. In the light of these results, it can be said that the use of both models together can contribute increasing usability much more