SERBIA

methodologies. We present an extension of cognitive model for HCI- (XUAN/t), based on decomposition of user dialogue into elementary actions (GOMS). Using this model, descriptions of elementary (sensor, cognitive and motor) actions performed by user and system are introduced sequentially, as they will happen. Based on the described model and psychometric concepts, we developed software CASE tool for testing cognitive as well as psychomotor abilities of a user in HCI. Software tool arranges tests into test groups for psychosensomotor and memory capabilities. User test results are persistently stored in a database and available for further statistical analysis. The main research goal was suitability verification of different HCI techniques for special user groups. Case study was performed and numerical results verifying the proposed model are presented in the paper