This document summarizes a presentation about using TIMSS 2011 data to analyze the relationship between opportunity to learn (OTL) factors, socioeconomic status (SES), and mathematics achievement. The presentation discusses using multilevel models to account for student, classroom, school, and country-level variables. It finds that SES variables significantly reduce variance at the classroom and country levels, while OTL variables also reduce variance but to a lesser degree. OTL is a significant predictor of achievement at the classroom level but not the country level, suggesting classroom/teacher factors play a bigger role than national curriculum.