It is a kind of assessment tools to measure the performance of education in one country compared to other countries.

International benchmarked assessment can be a literacy assessment such as "PISA" (Program for International Student Assessment (PISA):
http://nces.ed.gov/surveys/pisa/

Or
a curriculum-based assessment such as "TIMSS" (Trends in International Mathematics and Science Study):
http://nces.ed.gov/timss/