The aim of the presented study was to conduct an analysis of TIMSS 2003 database and to determine how negative school factors, such as aggression, are associated to the mathematical and science achievement of students. The analyses were conducted separately for national and international data. National analyses for Slovenia show significant associations between math and science achievement and the experience of aggressive behavior. Students who experienced aggressive behavior scored lower in math and science, both in the 4 th and 8 th grade. The results of the regression analysis show that negative factors, such as aggressive behavior, are good predictors of educational achievement in Slovenia. International analyses for the selected countries (high and low achieving countries from the whole TIMSS population) confirm that this type of finding is culturally impartial as well as valid for the level of achievement both in math and science.

Originally designed in the nineties to gather subjective perspective of the importance and existence of certain children's rights at home and at the school, by students and significant adults, using cross-culturally comparable methodology, the study evolved to gather a number of subjective quality of life assessment indicators. Survey study with different types of closed questions. Three measurements in Slovenia in the last decade, 2,000-3,000 students each sweep, and smaller samples in three other countries. Data base has been built on the importance and existence of key quality of life variables and assessments of the proper age to assume certain adult-like rights that enables comparisons of values cross-culturally and between age groups, and national trends that suggest slight degradation of the quality of life of children in last 15 years. The data gathered using this methodology proved to be culture sensitive (reflecting value hierarchies of rights in different countries), age sensitive (reflecting the evolving capacities of the child to grasp more sophisticated levels of rights and the quality of life assessments), useful tool for monitoring changes in the attitudes of (different groups of) adults towards children in the times of social change and transition, and other measures. The elements of the methodology could be used in future efforts to provide such subjective indicators on a broader international scale, as well as for national monitoring of the quality of life of children.