In a data search system, a user interface is implemented which can present results of data search in a human-recognizable fashion. The data search system includes an image processing unit for displaying a data search result based on a certain search criterion, as a set per search criterion, as well as converting each set into a polygonal Venn diagram, e.g. a dodecagon, having an area corresponding in magnitude to the number of elements in each set. The system also includes a display control unit for causing each Venn diagram to be displayed on a predetermined display device. Each of the multiple Venn diagrams is displayed on the same display screen while keeping its relative relationship with other Venn diagrams based on their search criteria.