Investigating of school effects on student achievement: A multilevel analysis of Turkey's TIMSS 2015 data

This study was conducted to investigate the effect of schools on student achievement in the context of some school-level variables. The research is a descriptive study in sense of correlational model. In this study, school effectiveness research approach was used and student' socioeconomic status (SES) was controlled in the analyses to determine the effect of school-level variables on student achievement differences. TIMSS 2015 Turkey's 4th and 8th grades mathematics datasets were the data source of this research. The study involves 6241 4th-graders from 242 primary schools and 6040 8th-graders from 218 middle schools which participated in TIMSS 2015 from Turkey. Datasets were analyzed with two-level Hierarchical Linear Modelling technique. Findings from this research showed that 37.6% and 35.6% of total variance of students' achievement in 4th and 8th grade is due to differences between schools respectively. However, about half of achievement variance observed at school level can be explained by SES differences of students. Socioeconomic composition of school and school emphasis of academic success at school level variables were found to have a significant effect on achievement for both grades. On the other hand, there was no significant relationship between the school' teaching resources and teacher characteristics (job satisfaction, cooperation and self-confidence) and achievement in both class levels. As a result, about two-thirds of achievement differences observed between schools for grades 4 and 8 were explained by socioeconomic status of student, socioeconomic composition of school, and school emphasis of academic success.