Reading Literacy

U.S. Student Performance on PIRLS 2001

PIRLS 2001 scores are reported on a scale of 0 to 1000, with an international average of 500 and a standard deviation of 100¹. For the 35 countries that participated in PIRLS 2001, figure 3 presents the average scores for the three scales: the combined reading literacy scale and its two components, the literary and informational subscales² .

U.S. Student Performance on the Combined Reading Literacy Scale

• U.S. fourth-grade students perform significantly better than the international average of 500 on the combined reading literacy scale (figure 3)³ .
• U.S. fourth-graders outperform their counterparts in 23 of the 34 other countries participating in PIRLS 2001, although they score lower than students in England, the Netherlands, and Sweden. No detectable differences in scores are found between U.S. students and their counterparts in eight of the remaining PIRLS 2001 countries.

U.S. Student Performance on Subscales

• U.S. fourth-grade students perform better than the international averages on both of the reading subscales (figure 3).
• Sweden outscores the United States on the literary subscale, and five countries-Bulgaria, England, Latvia, the Netherlands, and Sweden-outperform the United States on the informational subscale.
• U.S. fourth-graders outscore students in 26 countries on the literary subscale and outperform their counterparts in 17 countries on the informational subscale.

1 The international average is the mean of all countries participating in the study calculated so that all participating countries have the same contribution to the average. The PIRLS 2001 scale average for each scale (the combined reading literacy scale and the literary and informational subscales) across countries was set to 500 and the standard deviation to 100. Since the countries varied in size, each country was weighted to contribute equally to the mean and standard deviation of the scales. The average and standard deviation of each of the scale scores are arbitrary and do not affect scale interpretation. The standard deviation is the statistical measure of the extent to which values are spread around the average.
2 Average scores for each country are based on a sample of students, rather than all students, and are estimates of the population value of all 9-year-olds in each country. These estimates have a known degree of sampling error, the standard error, and an unknown degree of nonsampling error. The true average for any country lies within a range of approximately two times the standard error above and below the estimated score (also known as the confidence interval). The combined reading literacy scale is based on the distribution of scores on all the test items, while the subscales are based on only the items that belong to each subscale. Hence, the combined reading literacy score is not the statistical average of the scores of the two subscales.
3 All differences discussed in this report are statistically significant. No statistical adjustments (such as Bonferonni) are made while carrying out multiple comparisons between the United States and other countries. The t-tests used (in this report) do not adjust for the correlation between the U.S. average and the international average in order to be consistent with the comparisons carried out for the international report.