For example, in case of a college scholastic ability test, the proportion among chapters has been maintained similarly every year, thus it can be analyzed that most college scholastic ability tests have similar characteristics when using prior art analysis method. However, the college scholastic ability test actually has different characteristic year by year, thus the analysis using prior art method cannot have high reliability.

Even in the case that the above-described simplified indication is not conducted with respect to problems made based on a plurality of concepts or chapters in prior art, the characteristic of a problem set can be a mere aggregation of concepts or chapters, on which each problem is based, according to prior art. According to such prior art, in the process of analyzing characteristic of a problem set, it is hard to distinguish problem 1, which is based on two combined concepts of limit and similarity of figures, from problem 2, which is based on separate concepts of limit and similarity of figures, thus precise analysis is hard to achieve.

An objective of present invention, which starts from recognition of above-described prior art problems, is to provide method for indicating characteristic of problem and problem set, in which characteristic of problem and problem set can be precisely noted using correlations between attributes.

A different objective of present invention is to provide method for indicating characteristic of problem and problem set, in which characteristic of problem and problem set can be visualized by indicating attributes as points and indicating correlations between attributes as lines.