That is, with reference to FIG. 6, only the information on the presence of attributes and correlations between attributes can be obtained through the depicted screen, according to the method for indicating characteristic of problem set according to the first embodiment of the present invention.

In contrast, with reference to FIG. 11, not only the information on the presence of attributes, but also the information on how many times the attributes are included in the problem set, can be additionally obtained. Also, with reference to FIG. 11, not only the information on the presence of correlations between attributes, but also the information on how many times the correlations between attributes are included in the problem set, can be additionally obtained.

Specifically, with reference to FIG. 12, the characteristic of problem set analyzed according to the method for indicating characteristic of problem set according to the above-described fourth embodiment of the present invention is depicted. According to this, through the thickness of the line indicating the correlations between attributes, the importance of the correlations between attributes in the characteristic of problem set can be intuitively understood.

According to the method for indicating characteristic of problem set according to the fourth embodiment of the present invention, since the frequency of attributes and the frequency of correlations between attributes can be intuitively understood through the accumulative indication of characteristic of problem set, which is visually displayed on a screen, a more precise understanding of characteristic of problem set is possible.