WASHINGTON -- A widely publicized test that showed U.S. 12th-graders trailing other countries in math and science was based on flawed methods that distorted the results, an education professor contended Thursday in a scientific journal.
Iris C. Rotberg, research professor of education at George Washington University, said the Third International Mathematics and Science Study "tells us little about the quality of education" in the United States or other countries. The critique appeared in Science, the journal of the American Association for the Advancement of Science.
The latest test results, released in February, showed U.S. 12th-graders performed below the international average in a 21-nation comparison of students in their final year of secondary school. They did even worse in a comparison of those who took physics and advanced mathematics.
President Clinton called the results inexcusable.
The critique, however, says the international comparisons are invalid because the characteristics and numbers of students varied from country to country.
In countries where fewer students finish school, for example, results are higher because the poorer students have been weeded out. Also, secondary school lasts longer in some countries, so "older, more advanced students" scored higher. Other students attended specialized schools that focused on science and math, while the Americans were chosen from all kinds of schools, even vocational ones.
The study also ignored the role of poverty and related problems such as crime, violence and poor health and nutrition, the critique said.
Many of the criticisms have been voiced before, and the Education Department has addressed them in speeches and statements by Pascal D. Forgione Jr., U.S. commissioner of education statistics.
Among Forgione's points:
-- The test is meant to compare students at a similar point in the educational system -- the end of secondary school -- not students of the same age or year of schooling.
-- The age gap has been overstated. Although students from Iceland averaged 21.2 years and U.S. students, 18.1, the international average was 18.7. The gap was narrower for students taking advanced courses. Besides, schooling starts at a later age in some countries.
-- Among 17-year-olds, the United States had a higher percentage enrollment, so scores should have been higher.
-- Questions on the general knowledge test were based on material that would have been covered by the ninth grade for math and 11th grade for science in the United States.