Therefore, according to the method for indicating characteristic of problem set according to the sixth embodiment of the present invention, when comparison is made between different problem sets, different problem sets can be indicated in identical coordinates. Thus, with reference to FIG. 8, the above-described fixed type visualization facilitates comparison between different problem sets.

Hereinafter, with respect to FIG. 17, the method for indicating characteristic of problem set according to the seventh embodiment of the present invention is explained. The explanation will be focused on the difference from the method for indicating characteristic of problem set according to the sixth embodiment of the present invention. With reference to FIG. 17, a movable type embodiment according to the method for indicating characteristic of problem set according to the seventh embodiment of the present invention is depicted.

According to the method for indicating characteristic of problem set according to the seventh embodiment of the present invention, in a step of visualizing determined characteristic of problem set, the location of a point corresponding to specific attribute can be variable, non-fixed type or movable on a screen. For example, the attributes having a lot of correlations or found to be important can be indicated as collection of points on a screen. Also, the frequently included attributes may be indicated collectively in the middle of a screen. That is, the location of a point corresponding to specific attribute is not fixed on a screen, thus the visualization according to characteristic of each problem set becomes easier for a user to understand.