Three main testing instruments are used to gather international data on student achievement: PISA, TIMSS, and PIRLS: Program of International Student Assessment (PISA), Trends in International Mathematics and Science (TIMS), and Progress in International Reading (PIRLS).

PISA is administered by the Organization for Economic Co-operation and Development (OECD). This is a Europe-based entity. The PISA survey is given every three years to representative 15-year-olds in participating countries. The test is not tied to any specific curriculum. Its purpose is to assess 15-year-olds' competencies in the key subjects of reading, mathematics and science in terms of the students’ readiness to participate in adult life.

TIMS is administered by the International Association for the Evaluation of Educational Achievement (IEA), it’s given every four years to fourth- and eighth-grade students. TIMS tests mathematics and science. In 2011, about 520,00 students in 60 educational systems took the assessment.

PIRLS is the newest of the international testing programs. Also coordinated by the IEA, it was first given in 2001 to fourth-grade students in 36 participating educational systems including both countries and subnational entities such as Hong Kong. Since 2001, it has been given twice more, most recently in 2011 with 53 systems participating.

TIMS Test Content
Mathematics
Grades 3 and 4: Whole Numbers; Fractions and Proportionality; Measurement, Estimation, and Number Sense; Data Representation, Analysis, and Probability, Geometry, Patterns, Relations, and Functions.

Grades 7 and 8: Whole Numbers; Fractions and Proportionality; Measurement, Estimation, and Number Sense; Data Representation, Analysis, and Probability, Geometry, Patterns, Relations, and Functions.

TIMS Test Content
Science
Grades 3 and 4: Earth Science. Life Science, Physical Science, Environmental Issues and Nature of Science

Grades 7 and 8: Earth Science. Life Science, Physical Science, Environmental Issues and Nature of Science

PIRLS Reading Questions
On this test, fourth-graders must read short selections, either fictional or informational, and answer both 4-part multiple choice questions and short answer questions that require writing a few words.

All three of these testing instruments are useful to government planners in various countries. Interpreting them as indications of the superiority of one educational system over another, however, is an exercise in futility.

Time spent in school is only a part of the educational equation. Social and cultural conditions determine to a large part what a child is going to learn in school.