SUMMARY
In the field of education, most of the data collected are multi-level structured. Cities, city based schools, school based classes and finally students in the classrooms constitute a hierarchical structure. Hierarchical linear models give more accurate results compared to standard models when the data set has a structure going far as individuals, groups of individuals and communities of groups. In this study, the effects of the school level indicators on overall reading skills performance of 15 year-old group students within PISA 2015 Turkey application, are analyzed by using a two level hierarchical linear model. In the study, apart from sex, socioeconomic indicators of family, education level of the parents and some student level indicators regarding reading skills, school level indicators such as school type, number of students and number of teachers are also integrated to modelling process to reflecting the hierarchical data structure into the statistical model. At the end of the modelling process, factors that effects the reading skills are determined.