This paper is devoted to the study of methods for assessing the effectiveness of public information systems that can identify the relationship between the characteristics of individual factors of their creation and assess the impact of these factors on their overall effectiveness and ability to create public values. After reviewing, selecting and adapting an evaluation methodology, it was tested with several e-participation portals. This choice was due to both the growing interest in increasing the effectiveness of these portals, and the relative availability of initial information for analysis. During the research, a number of hypotheses were formulated and tested. The results obtained and presented in this paper confirm the suitability of the chosen methodology to solve the stated tasks of effectiveness assessment of government information systems and the influencing factors.