This article, based on the global logic of dissemination of the "Octopus" project, assumes as its main aims: i) the creation of an instrument to evaluate the application of the usability tests of the users'graphic interfaces (in the alpha version of the prototype), according to the heuristic method of evaluation of graphic interfaces (Nielsen, 1993); ii) to contextualize the usability tests of the resource centre's graphic interfaces, in the frame of the global project evaluation.Considering the body of reasons that guided the development of an instrument to assess the usability of the resource centre graphic interfaces, it is important to bear in mind the aims of the project. These are based on a logical of development of interfaces (human-machine), facilitators of the interaction between the users of "Octopus" and the computer that supports the functions offered by the resource centre.