Skip Navigation

Frequently Asked Questions

In addition to the following questions about PIRLS, more FAQs about international assessments are available at:

What is PIRLS?

The Progress in International Reading Literacy Study (PIRLS) is an international assessment and research project designed to measure trends in reading achievement at the fourth-grade level as well as school and teacher practices related to instruction. Since 2001, PIRLS has been administered every 5 years. PIRLS 2016, the fourth study in the series, involves students from 61 education systems, including the United States (however, the U.S. only reports findings for 58 countries because 3 education systems tested students in grades higher than fourth grade). For the first time, PIRLS is also administering an innovative assessment of online reading called ePIRLS.

What is ePIRLS?

ePIRLS is an innovative assessment of online reading which makes it possible for countries to understand how successful they are in preparing fourth grade students to read, comprehend, and interpret online information. The first administration of ePIRLS was in 2016; it was administered in 16 education systems. More information on ePIRLS can be found in the IEA ePIRLS brochure, by trying out the ePIRLS assessment at Take the ePIRLS Assessment, and by watching videos available at

What questions can PIRLS answer?

PIRLS is a carefully constructed reading assessment, consisting of a test of reading literacy and questionnaires to collect information about 4th-grade students' literacy performance.
PIRLS can help educators and policymakers by answering questions such as:

  • How well do 4th-grade students read?
  • How do students in one country compare with students in another country in reading literacy?
  • Do 4th-grade students value and enjoy reading?
  • Internationally, how do the reading habits and attitudes of students vary?

What aspects of reading literacy are assessed in PIRLS?

PIRLS focuses on three aspects of reading literacy:

  • purposes of reading;
  • processes of comprehension; and
  • reading behaviors and attitudes.

The first two form the basis of the written test of reading comprehension. The student background questionnaire addresses the third aspect.

In PIRLS, purposes of reading refers to the two types of reading that account for most of the reading done by young students, both in and out of school: (1) reading for literary experience, and (2) reading to acquire and use information. In the assessment, narrative fiction is used to assess students' ability to read for literary experience, while a variety of informational texts are used to assess students' ability to acquire and use information while reading. The PIRLS assessment contains about an equal proportion devoted to each of these two purposes.

Processes of comprehension refer to ways in which readers construct meaning from the text. Readers focus on and retrieve explicitly stated information; make straightforward inferences; interpret and integrate ideas and information; and evaluate and critique content, language, and textual elements.

For more information on the purposes for reading and processes of comprehension, see the PIRLS 2016 Assessment Framework.


What are the components of PIRLS?

The assessment instruments include 4th-grade-level stories and informational texts collected from several different countries. Students are asked to engage in a full repertoire of reading skills and strategies, including retrieving and focusing on specific ideas, making simple and more complex inferences, and examining and evaluating text features. The passages are followed by open-ended and multiple-choice format questions about the text.

The 2016 assessment consists of 15 booklets and 1 reader (presented in a magazine-type format with the questions in a separate booklet). The assessment is given in two 40-minute parts with a 5- to 10-minute break in between. Each of the booklets contains two parts—one block of literary experience items and one block of informational items—and each block occurs twice across the 15 total booklets. As the entire assessment consists of 12 blocks of passages and items, using different booklets allows PIRLS to report results from more assessment items than can fit in one booklet, without making the assessment longer. To provide good coverage of each skill domain, the test items developed require about 8 hours of testing time. However, testing time is limited to 80 minutes per student by clustering items in blocks and randomly rotating the blocks of items throughout the student test booklets. As a consequence, no student receives all items (there were a total of 175 items on the 2016 assessment), but each item is answered by a representative sample of students.

A total of 12 reading passages—two from PIRLS 2001, 2006 and 2011, two from 2006 and 2011, two from PIRLS 2011 only, and six new passages—are included in the 2016 assessment booklets used in all participating education systems. The use of common passages from the 2001 through the 2016 assessments allows for the analysis of change in reading literacy over the 15-year period between administrations for countries that participated in these cycles. The passages, as well as all other study materials, were translated into the primary language or languages of instruction in each education system.

Background questionnaires are administered to collect information about students' home and school experiences in learning to read. A student questionnaire addresses students' attitudes towards reading and their reading habits. The student questionnaire is administered after the assessment portion, taking about 30 minutes to complete. In all, PIRLS takes 1 to 2 hours of each student's time, including the assessment and background questionnaire.

In addition, questionnaires are given to students' teachers and school principals to gather information about students' school experiences in developing reading literacy. The teacher and school questionnaires are administered either online from a secure website or via a hardcopy form. Teacher questionnaires take about 40 minutes to complete and ask teachers questions about their education and experience, available resources, and instructional practices. School questionnaires take about 40 minutes to complete and ask about school practices and resources.

In many countries (but not the United States), a parent questionnaire is also administered.

What are the components of ePIRLS?

Similar to PIRLS, the ePIRLS assessment consists of five tasks, but students are asked to complete only two of the five 40-minute tasks. Completion of the tasks takes place on a computer. Each task contains school-based online reading tasks, each of which involves two to three different websites totaling five to ten web pages, for which students are then asked to complete a series of comprehension questions based on the task. Students also complete a brief survey about their online access, knowledge, and use. ePIRLS takes about 2 hours of the student's time, including the assessment and questionnaire.

What is the data collection schedule?

In both hemispheres, PIRLS is conducted near the end of the school year. Thus, for PIRLS 2016, countries in the Southern Hemisphere conducted the study between October and December, 2015. Countries in the Northern Hemisphere conducted the study between March and June, 2016.

ePIRLS was typically completed in the school one day after the PIRLS session.


What is the sample design?

Each participating country agrees to select a sample that is representative of the target population as a whole. In 2001, the target population was the upper of the two adjacent grades with the most 9-year-olds. For PIRLS 2006, 2011, and 2016, the definition of the target population was refined to represent students in the grade that corresponds to the fourth year of schooling, counting from the first year of International Standard Classification of Education (ISCED) Level 14th grade in most countries, including the United States. This population represents an important stage in the development of reading. At this point, generally children have learned to read and are using reading to learn. IEA's Trends in International Mathematics and Science Study (TIMSS) has also chosen to assess this target population of students.

In each administration of PIRLS, schools are randomly selected first (with a probability proportional to the estimated number of students enrolled in the target grade) and then one or two classrooms are randomly selected within each school. In 2001, a nationally representative sample of 3,763 U.S. 4th-grade students was selected from a sample of 174 schools. In 2006, a nationally representative sample of 5,190 U.S. 4th-grade students was selected from a sample of 183 schools. In 2011, a nationally representative sample of 12,726 U.S. 4th-grade students was selected from a sample of 370 schools.

The reason for a larger sample size in 2011 than in previous administrations of PIRLS was that in 2011 both TIMSS and PIRLS happened to coincide in the same year. The decision was made to draw a larger sample of schools and to request that both studies be administered in the same schools (where feasible), albeit to separate classroom samples of students. Thus, TIMSS (grade 4) and PIRLS in the United States were administered in the same schools but to separately sampled classrooms of students.

In the spring of 2016, 4,425 students from 158 schools nationwide participated in the PIRLS Main Study. Within each school, 4th-grade classrooms were randomly selected to represent the nation's 4th-graders. All students from selected classrooms were invited to participate in the PIRLS main study. These same students participated in ePIRLS, typically on the day following the PIRLS administration. Of the 158 schools participating in PIRLS, 153 schools and 4,090 students participated in ePIRLS.

Which countries are participating?

The table below lists the total number of education systems that have participated in each of the four administrations of PIRLS at grade 4. This number includes both countries and subnational entities, such as Canadian provinces, U.S. states, England, and Hong Kong. For more information on participating education systems, including a complete list of education systems participating in ePIRLS, visit the PIRLS Country Page.

Year Education systems participating
in PIRLS at grade 4*
2001 36
2006 45
2011 53
2016 58
*Education systems with off-grade
participants not included.


How are PIRLS and ePIRLS developed and administered?

PIRLS and ePIRLS are a cooperative effort involving representatives from every education system participating in the study. Prior to each administration of PIRLS, the framework is reviewed and updated to reflect changes in the curriculum and instruction of participating education systems, while maintaining the ability to measure change over time. Extensive input is received from experts in reading education, assessment, and curriculum, as well as representatives from national education centers around the world.

In order for educators, policymakers, and other stakeholders to better understand the results from PIRLS, many assessment items are released for public use after each administration. To replace these items, countries submit items for review by subject-matter specialists, and additional items are written by a committee in consultation with item-writing specialists in various countries to ensure that the content, as explicated in the frameworks, is covered adequately. Items are reviewed by a committee and field-tested in most of the participating education systems. Results from the field test are used to evaluate item difficulty, how well items discriminate between high- and low-performing students, evidence of bias toward or against individual countries or in favor of boys or girls, etc. In 2016, 95 new items were selected for inclusion in the international assessment and added to 80 existing items. PIRLS is administered as a pencil-and-paper assessment and includes both multiple choice and constructed response items. The item pool contains a selection of literary passages drawn from children's storybooks and informational texts. Literary passages include realistic stories and traditional tales, while informational texts include chronological and nonchronological articles, biographical articles, and informational leaflets.

ePIRLS is designed to be an extension of PIRLS. Because the 2016 data collection marked the first administration of ePIRLS, all items were newly developed. Two of the tasks will be released for public use and the rest will be retained to measure trends across future ePIRLS cycles. Students complete the ePIRLS tasks on a computer where they read information on 2-3 simulated websites and answer a series of comprehension questions.

How does PIRLS compare to the NAEP fourth-grade reading assessment?

Three studies have compared PIRLS and NAEP in terms of their measurement frameworks and the reading passages and questions included in the assessments. The most recent study compared NAEP with PIRLS 2011 (see Highlights from PIRLS 2011, appendix C). Prior studies compared NAEP with PIRLS 2001 (A Comparison of the NAEP and PIRLS Fourth-Grade Reading Assessments PDF icon)  and compared NAEP with PIRLS 2006 (Comparing PIRLS and PISA with NAEP in Reading, Mathematics, and SciencePDF icon)—compared NAEP with PIRLS 2006. The studies found the following similarities and differences:


  • PIRLS and NAEP call for students to develop interpretations, make connections across text, and evaluate aspects of what they have read.
  • PIRLS and NAEP use literary passages drawn from children's storybooks and informational texts as the basis for the reading assessment.
  • PIRLS and NAEP use multiple-choice and constructed-response questions with similar distributions of these types of questions.


  • Results of readability analyses suggest that the PIRLS reading passages are easier than the NAEP passages (by about one grade level, on average).
  • PIRLS calls for more text-based interpretation than NAEP. NAEP places more emphasis on having students take what they have read and connect to other readings or knowledge and to critically evaluate what they have read.


Where can I get a copy of the PIRLS U.S. Report?

The PIRLS U.S. Reports are all available for download from the NCES website. Links are provided below.

Year Publication
2016 Reading Achievement of U.S. Fourth-Grade Students in an International Context: First Look at the Progress in International Reading Literacy Study
2011 Highlights From PIRLS 2011: Reading Achievement of U.S. Fourth-Grade Students in an International Context
2006 The Reading Literacy of U.S. Fourth-Grade Students in an International Context: Results from the 2001 and 2006 Progress in International Reading Literacy Study (PIRLS)
2001 International Comparisons in Fourth-Grade Reading Literacy: Finding from the Progress in International Reading Literacy Study (PIRLS) of 2001

Find additional PIRLS publications under Publications & Products.

When will PIRLS be administered again?

The most recent PIRLS administration was in 2016 with the release of PIRLS results in December 2017. The next administration is scheduled for 2021.

Which schools are selected for participation?

Schools of varying demographics and locations are randomly selected so that the overall U.S. sample is representative of the overall U.S. school population. The random selection process is important for ensuring that a country's sample accurately reflects its schools and, therefore, can be compared fairly with samples of schools from other countries.

Are all fourth-grade students in a school asked to participate?

In schools with only one or two fourth-grade classrooms, all students are asked to participate. In schools with more than two fourth-grade classrooms, only students in two randomly selected classrooms are asked to participate. Some classrooms selected to participate in PIRLS are also asked to take part in ePIRLS. In classrooms that are also asked to participate in ePIRLS, PIRLS is administered on day one and ePIRLS on a second day. In addition, some students with special needs or limited English proficiency may be excused from the assessment.