1) The document discusses a study that uses TIMSS 2011 data to examine the role of opportunity to learn (OTL) factors in geometry achievement across six countries.
2) It develops a framework called the DOC framework that examines OTL at the national, school/classroom, and student levels, with a focus on curriculum-related variables.
3) Preliminary results show differences between countries in factors like socioeconomic status, homework time, geometry instruction time, and teacher preparedness, and their relationships with achievement vary in complex ways between countries.