A graphical user interface for an information mediation system is provided for assisting the user to discover an information source that matches a sense of value of the user which normally can not be explicitly expressed in language, from a plurality of information sources such as bulletin board sites. The information mediation apparatus collects information from the plurality of information sources, analyzes the information, and generates one or more guideposts corresponding to information values thereof and data indicating a correlation between the plurality of information sources relative to the guideposts. A client apparatus receives one or more guideposts and a set of data containing information indicating the correlation of the information sources relative to the guidepost from the information mediation apparatus, and displays the correlation between these information sources in such a mode that the user can easily understand.