EN
The article deals with the quality of data obtained in the quantitative research process. The authors decided to raise the subject, because in the Polish political science – in the opposition to sociology – it’s not well described. The text was made mainly on the basis of a literature review devoted to particular parts of the article and is its synthesis. During the work it was discovered that thanks to relatively simple tools, as well as the use of some programs the quality of the data set can be checked in a simple and precise way.