The article describes the features of actual automated information systems (IS) and problems of formation and intellectualization of user interfaces providing the interactive computer solving of information tasks. It is dwelled on the scheme of user interface; special attention is paid to the input of subject field particularity knowledge into IS. The authors come to the conclusion that problems of communication between user and computer require special means allowing to put into practice the effective interaction with information systems at their working, usage and development stages as a whole. Besides, it is pointed out that due to WEB-technology that promoted the Internet as a global information system the problem of effective interaction between user and IS has become more actual and needful.