The exam was first administered in 2000 to measure the performance of 15-year-olds in the 35 industrialized countries of the Organization for Economic Cooperation and Development (OECD) and has been administered every three years since. It has expanded beyond the 35 member countries. In 2018, 600,000 students from 79 countries took the exam.
And for about as long, the exam has faced a chorus of skeptics who caution reading too deeply in to the results. Students are not penalized for performing poorly and never see their results, and students in the United States tend to be less motivated to perform well on it compared with teens in other countries, according to recent studies.
“We need to interpret these scores with caution,” University of California at San Diego economist Sally Sadoff said. “People wring their hands when they see these scores and say the U.S. is falling behind, and that may be true, but we want to caution that these test scores are not a pure measure of students’ ability, knowledge and learning.”
Reading and math scores for U.S. students have not changed significantly since the exam debuted, while there have been some improvements in science. That trend continued in 2018, when student scores across all three subjects were virtually unchanged from 2015.
Several countries lost ground, boosting the ranking of the United States, which ranked eighth in reading and 11th in science. Its math score — below the average for other countries in the OECD — put it at 30th in the world, according to the National Center for Education Statistics.
Peggy G. Carr, associate commissioner of the assessment division at the National Center for Education Statistics, said the results sent an unmistakable message that U.S. students are in trouble when it comes to how they perform in math relative to their international peers. “The rankings are telling,” Carr said.
The results are just the latest sign of growing disparities in academic performance. On the National Assessment of Educational Progress, an exam given to students to gauge the nation’s academic performance, scores tumbled for fourth- and eighth-graders this year in reading. Eighth-graders lost ground in 30 states. Low-performing readers slipped even more than their higher-performing peers. There were similarly worrisome results in 2018 on the national assessment test, when scores remained constant but lower-performing students lost ground.
And three years ago, scores for U.S. fourth-graders on a global literacy assessment fell, with the lowest-performing students losing the most ground.
“That should throw up red flags for everyone,” Carr said.
“Should we be worried about this?” said Andreas Schleicher, director of education and skills at the OECD. “I do think so, because . . . our labor markets were a lot more tolerant of educational failure in the past than they are now. So I think students who do not make the grade face pretty grim prospects.”
The exam is designed to accurately gauge the abilities of students from country to country because it is low-stakes, meaning more affluent students do not have an incentive to pay for special test preparation. But those administering the exams to teenagers have encountered serious motivation issues. Economists have found mounting evidence that the gap in scores between countries reflects a gap in effort as much as it does a gap in achievement. By both measures, the United States lags behind.
In one experiment, researchers found that U.S. students were far more responsive when they were offered money for correct answers than students in Shanghai. The results suggest U.S. students are intrinsically less motivated to do well on such assessments.
Other researchers have produced similar results by pinpointing the slackers among the hundreds of thousands of students who took the computerized version of the test, and adjusting the results accordingly.
“Countries differ a lot by this degree of non-seriousness,” said Jinwen Wang, a doctoral student at Pennsylvania State University who has studied the phenomenon. “As a result, the rankings paint a distorted picture of where countries stand in both absolute and relative terms.”
Differences in effort explained between 32 percent and 38 percent of the international differences in PISA scores in 2009, according to a recent Journal of Human Capital analysis.
The biggest problem was students who never engaged with the exam, which economists measured in part by looking at students’ effort in a follow-up survey. The second biggest factor? A lack of test endurance.
In some countries, such as Spain, performance began high, but fell quickly. Others, such as South Korea, began in the middle of the pack but, through consistent effort, emerged near the top. The United States fits somewhere between the extremes.
“How much effort kids put on this type of assessment might be capturing what we call character skills, like conscientiousness and self-control, that research has found is very important for later-life outcomes,” said Gema Zamarro, a University of Arkansas education professor who has studied PISA results. “It’s not that the PISA test is not useful. It’s that it may be even more useful than a test that focuses only on knowledge.”