GradeStat is a program which was specifically developed for statistical use mainly for data analysis. GradeStat was developed with the combined effort of many people who worked together in the Institute of Computer Science of the Polish Academy of Sciences. The grade analysis is the basis for the creation of this program. The grade analysis is said to be the one responsible for allowing the fast investigation of large sets of data. One of the program’s unique properties includes the capability to visualize the output with the use of two different types of maps: the dependence indences and the over-representation. The GradeStat program has two different books which were published through a combined effort of The Children’s Memorial Health Institute and Institute of Computer Science PAS. The Children’s Memorial Health Institute is the one responsible for providing the medical data which were used in one of the books.