The quality of education is increasingly being measured less by the knowledge gained during schooling and more by the level of competence possessed by students at doing a particular job after completing their education. Target and process-planned curricula are being replaced more and more by competenceoriented curricula, especially in science and technology education, where competences, generally defined as the ability of an individual to do a job properly, are placed at the forefront. In these, skills are not understood primarily as cognitive skills (e.g. critical thinking), but mostly as skills in connection to psychomo torics. If competence is the desired criterion for educational quality, it can be easily established that suitable instruments and methods of measurement are needed for this kind of quality evaluation, which, however, are not yet available. This is why in the field of competences a special unified competences taxonomy was developed, based on different taxonomies for the cognitive and also affective and psychomotor fields. Additionally, suitable instrumentation was developed in this study. Its use was demonstrated in the example of elementary education in Slovenia in the field of science and technology education.