Introduction

TIMSS 2015 Achievement Results and Context Questionnaire Data

The TIMSS 2015 Encyclopedia provides a qualitative complement to the two quantitatively oriented international reports that summarize the achievement results and the background data collected about school and classroom environments. The upcoming TIMSS 2015 International Results in Mathematics summarizes fourth and eighth grade students’ trends in mathematics achievement, and provides considerable information about how mathematics is taught in schools.² The companion report, TIMSS 2015 International Results in Science, contains fourth and eighth grade students’ trends in science achievement and related data concerning science instruction.³ To provide trends in mathematics and science achievement in the context of schools and classrooms with diverse policies, practices, and resources, the students assessed in TIMSS and their teachers and school principals completed questionnaires about their school and classroom conditions, including the background and experiences of teachers and students.⁴ Much of this information is provided together with the TIMSS achievement results in the TIMSS mathematics and science reports.