A sampling error in the U.S. administration of the most recent international test known as PISA resulted in average scores being lower than they should have been, according to a new report that questions just how much these international exams reveal about American public education.

The report released today, titled “What do international tests really show about American student performance?” was written by Martin Carnoy of the Stanford University Graduate School of Education and Richard Rothstein of the Economic Policy Institute.

Table Table 2A (continued)

Share of PISA 2009 sample in each social class group, by country

Social class group Canada Finland Korea France Germany U.K. U.S.
Group 1 (Lowest) 9% 6% 5% 15% 12% 14% 20%
Group 2 13 11 9 17 13 16 18
Group 3 31 34 31 31 29 29 28
Group 4 21 23 23 18 19 18 16
Group 5 17 20 22 13 16 15 12
Group 6 (Highest) 9 6 9 7 10 8 6

Source: Authors’ analysis of OECD Program for International Student Assessment (PISA) 2009 database for each country

The authors say that international test scores are often “interpreted to show that American students perform poorly when compared to students internationally,” and that school reformers then conclude that “U.S. public education is failing.” Such inferences, they say, “are too glib.”

Policymakers and analysts increasingly express consternation over the fact that average American scores on international exams are nowhere near the top — even though the United States has never done especially well on international exams. U.S. scores of students from low-poverty schools can match the world’s highest-performing countries but the average is brought down by scores from high-poverty schools.

The authors say that in every country participating in the exams, the poorest students perform the worst, and that social class inequality is greater in the United States than in any of the other countries that are reasonable comparisons. As a result, “U.S. average performance appears to be relatively low partly because we have so many more test takers from the bottom of the social class distribution.”

Results released last month from two international exams, the 2011 Progress in International Reading Literacy Study and the Trends in International Mathematics and Science Study, showed that American students had made some gains but lagged behind many of their Asian counterparts in reading, math and science. PISA is the Program for International Student Assessment that measures 15-year-old students’ reading, mathematics and science literacy.

Among the new report’s findings:

Because social class inequality is greater in the United States than in any of the countries with which we can reasonably be compared, the relative performance of U.S. adolescents is better than it appears when countries’ national average performance is conventionally compared.

 

Because not only educational effectiveness but also countries’ social class composition changes over time, comparisons of test score trends over time by social class group provide more useful information to policymakers than comparisons of total average test scores at one point in time or even of changes in total average test scores over time.