The access to computer technology has occurred in residential and school environments - not only for entertainment, but also for educational goals. Part of this process has been the use of educational sites by children in their homes and schools. However, on many occasions, users become disoriented in the system navigation due to misunderstanding problems of the graphics that indicate the navigation: the clickable areas. These difficulties may hind the achievement of educational goals. Then, it points out the importance of knowing the infantile users mental models, understanding the cognitive processes before an educational site interface and its actions are generated, in other words, the user external behavior during navigation. This research presents a field survey, where were collected quantitative and qualitative data related to the mental model structuring of the user while the navigation. A case study - in the Kiagito site, EduKbr portal part was chosen. Later, it were compared the users models with the system addressed usability model. The research was divided into two phases: exploratory and participatory. The exploratory phase was composed of three parts: 1) directed at education specialists, through interviews about hypermedia systems used in school; 2) directed at teachers, by applying Pedactice method; 3) directed at designers, by applying Ticese method. In the participatory phase, Co-discovery method was used with a children group according to their understanding and their behavior while navigating certain Kiagito website areas. The research data leads to the conclusion: reiterates the importance of cognitive processes from the interfaces’ design of the educational sites for children, having as a background the design, ergonomics and human-computer interaction interlace with education. It is considered that all these factors have crucial importance for the success between computer technology and education.