All questionnaires, regardless of what they measure, must demonstrate good performance with regard to psychometric properties. Psychometrics is a branch of survey research that has developed methods how to quantify errors in measurement because no matter how well is the questionnaire prepared, observed data bears except of desired true data also measurement errors. You should distinguish notion psychometrics from psychometrics used in sociological practice. There is no Slovak equivalent for psychometrics (as a branch of survey research) at the moment, although term psychometrics is common abroad and comprehended correctly. But we can also say we are introducing methodological requirements for data collected through the questionnaire surveys that should be satisfied prior to any statistical manipulation. Rehák (1998) noticed the quality of data determinate the quality of results. In general, questionnaires collecting research data should satisfy requirements of validity, reliability and feasibility. Criteria and standards in psychometrics are not defined as strict rules, but rather as ranges within you would expect certain indicators to fall if the questionnaire is operating correctly. Also the strict limit showing which and how many tests must be used to proof the quality of questionnaire is missing. According to the most of reviewed literature authors use the same set of tests that vary only in number of tests according to which psychometrics areas were tested. Methodology, how to test your quality of data collected through the questionnaire survey, is demonstrated on empirical Slovak data achieved through the Multi-country Survey Study (MCSS) questionnaire.