The target population included all students enrolled on a fulltime basis in the grade that contained the most 14-year-old students at the time of testing (eighth grade in the majority of countries). Some of the participating countries conducted an additional optional survey of upper-secondary school students (ages 17–19).
Austria, Belgium, Bulgaria, Chile, Colombia, Cyprus, Czech Republic, Denmark, England, Estonia, Finland, Germany, Greece, Hong Kong SAR, Hungary, Israel*, Italy, Latvia, Lithuania, Norway, Poland, Portugal, Romania, Russian Federation, Slovak Republic, Slovenia, Sweden, Switzerland, and United States.
*Israel tested only the older age group, not 14 year olds
The international coordinating center was , working in close cooperation with the IEA, and the national centers of participating countries.