Statistic of the Month: Comparing Low and High Performers on PISA 2018


by Jennifer Craw

Every three years the OECD’s Programme for International Student Assessment (PISA) assesses how well 15-year-old students from around the world can apply their knowledge in reading, mathematics and science to real-world situations. In 2018, the latest administration of the exam, 79 countries participated, and the focus domain – which rotates among reading, mathematics and science for each administration – was reading proficiency. US students performed at just above the OECD average in reading and science, and below the OECD average in mathematics.

PISA rates student performance on a six-point scale where students scoring at levels two and below are considered low-performing, and students score at levels five and six are considered high-performing. When student performance is broken down into these proficiency levels, more troubling patterns in the US’s performance emerge. 

In the following charts we compare US student performance in reading, mathematics and science to the performance of a small set of top-performing countries from around the world: Canada, Estonia, Singapore and China*.

In reading proficiency, where US students performed best, we do see a similar proportion of high-performing students in the U.S. as in Estonia and Canada, though not as large a proportion as in Singapore and China. However, we also see a significantly higher proportion of low-performing students in the U.S. (about 40 percent) than in any of the top-performing example countries. This suggests that the about-average performance of U.S. students in reading is driven by a small number of high-performing students and a large number of low-performing students.

The distribution of scores in science proficiency follow a similar pattern as seen in reading. Here the distribution of scores in China are the reverse of those in the U.S. Where the U.S. saw only about 10 percent of students in the high-performing category, China only saw about 10 percent of students in the low-performing category. 

In mathematics performance the achievement gap in the United States is at its most pronounced. More than half of all US students were low-performing in mathematics. Meanwhile, Estonia and Canada saw over 15 percent of their students scoring at the highest levels of proficiency, almost double the U.S. rate of about eight percent. And China saw more than 44 percent of students performing at the highest levels of mathematics – five times the proportion of U.S. students performing at that level.

For more on what the PISA results mean for the U.S., tune in on November 16th for a special webinar with Andreas Schleicher, Director for Education at the OECD, U.S. Department of Education’s Peggy Carr and NCEE’s Anthony Mackay as they explore lessons for the U.S. from PISA 2018. 

*China’s scores include students from four provinces: Beijing, Shanghai, Jiangsu and Zhejiang. Collectively these provinces have a population of 184 million, more than half the population of the United States.