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.
Share of PISA 2009 sample in each social class group, by country
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 in every country, students at the bottom of the social class distribution perform worse than students higher in that distribution, 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.
- A sampling error in the U.S. administration of the most recent international (PISA) test resulted in students from the most disadvantaged schools being over-represented in the overall U.S. test-taker sample. This error further depressed the reported average U.S. test score.
- If U.S. adolescents had a social class distribution that was similar to the distribution in countries to which the United States is frequently compared, average reading scores in the United States would be higher than average reading scores in the similar post-industrial countries we examined (France, Germany and the United Kingdom), and average math scores in the United States would be about the same as average math scores in similar post-industrial countries.
- A re-estimated U.S. average PISA score that adjusted for a student population in the United States that is more disadvantaged than populations in otherwise similar post-industrial countries, and for the over-sampling of students from the most-disadvantaged schools in a recent U.S. international assessment sample, finds that the U.S. average score in both reading and mathematics would be higher than official reports indicate (in the case of mathematics, substantially higher).
- This re-estimate would also improve the U.S. place in the international ranking of all OECD countries, bringing the U.S. average score to fourth in reading and 10th in math. Conventional ranking reports based on PISA, which make no adjustments for social class composition or for sampling errors, and which rank countries irrespective of whether score differences are large enough to be meaningful, report that the U.S. average score is 14th in reading and 25th in math.
- Disadvantaged and lower-middle-class U.S. students perform better (and in most cases, substantially better) than comparable students in similar post-industrial countries in reading. In math, disadvantaged and lower-middle-class U.S. students perform about the same as comparable students in similar post-industrial countries.
- At all points in the social class distribution, U.S. students perform worse, and in many cases substantially worse, than students in a group of top-scoring countries (Canada, Finland, and Korea). Although controlling for social class distribution would narrow the difference in average scores between these countries and the United States, it would not eliminate it.
- U.S. students from disadvantaged social class backgrounds perform better relative to their social class peers in the three similar post-industrial countries than advantaged U.S. students perform relative to their social class peers. But U.S. students from advantaged social class backgrounds perform better relative to their social class peers in the top-scoring countries of Finland and Canada than disadvantaged U.S. students perform relative to their social class peers.
- On average, and for almost every social class group, U.S. students do relatively better in reading than in math, compared to students in both the top-scoring and the similar post-industrial countries.
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.
- The performance of the lowest social class U.S. students has been improving over time, while the performance of such students in both top-scoring and similar post-industrial countries has been falling.
- Over time, in some middle and advantaged social class groups where U.S. performance has not improved, comparable social class groups in some top-scoring and similar post-industrial countries have had declines in performance.