Hierarchical linear modeling between student’s H^T person fit statistic and contextual variables in eight grade mathematics test for TIMSS 2015

Person fit assessment is useful in ensuring validity and fairness in the use and interpretation of test scores. In this research, applied the H^T person fit statistic to examine response pattern of TIMSS eight grade mathematics test of Australia, Iran, and Republic of Korea. In order to investigate the effect of contextual variables on students’ person fit statistic, hierarchical linear modeling was used, due to the hierarchical structure of data. Based on intraclass correlation coefficient, 83.7% of variance of the H^T person fit statistic is at student level, and 16.3% of variance of the H^T person fit statistic is at school and country levels. In addition, according to the hierarchy linear final model between the H^T person fit statistic and factors of students, schools, and countries; only the average of students mathematics achievement in countries, school emphasis on students academic success, students confident in mathematics, and estimate of students ability, are significant factors in the final model.