Programme for International Student Assessment 2025: national report for Scotland

2 Background and methodology

2.1 What is PISA?

The Programme for International Student Assessment (PISA), coordinated by the Organisation for Economic Co-operation and Development (OECD), is an international study of the knowledge and skills of 15 year old pupils. It focuses not simply on whether pupils can reproduce what they have learned, but on how well they can use their knowledge and skills to interpret information, reason and solve problems in real-life contexts.

The Organisation for Economic Co-operation and Development (OECD) is an intergovernmental organisation founded in 1961 to support governments to develop evidence-informed policies that improve people’s lives. The organisation has grown from 20 founding members in 1961 to 38 member countries in 2026.

PISA assesses performance in reading, mathematics and science, with one subject explored in greater depth in each cycle. In 2025, science was the main focus of the assessment. Each cycle also includes an additional ‘innovative’ domain designed to capture skills that are increasingly important in modern life. In 2025, this focused on ‘Learning in the Digital World’, which assesses pupils’ ability to build knowledge and solve problems using computational tools and practices.

Since its first cycle in 2000, PISA has expanded significantly and is now one of the world’s leading sources of comparative evidence on education systems. In 2025, 91 countries and economies took part, with around 760,000 pupils participating globally. Scotland has taken part in every cycle since the study began.

2.2 Scotland’s participation in PISA

Scotland participates in PISA as an adjudicated region of the United Kingdom. This means that a separate representative sample of schools and pupils is selected for Scotland through the internationally specified PISA sampling process, allowing Scotland to produce its own results rather than being represented only within UK-wide results. To achieve adjudicated region status, Scotland must meet the same international technical and quality standards as participating countries, allowing its results to be compared directly with education systems around the world.

In Scotland, the National Foundation for Educational Research (NFER) delivered the study on behalf of the Scottish Government. The assessment was carried out in schools between September and October 2025 using computer-based testing. This was earlier in the academic year than previous Scottish PISA cycles, reflecting changes to the international PISA timetable. In total, 115 schools and colleges, and 3,066 pupils took part, providing a representative picture of the performance of Scotland’s 15 year olds.

Participation in PISA 2025 met the OECD’s required standards. After taking account of the survey design, 87.9% of sampled schools and 80.1% of sampled pupils participated. These rates were similar to recent PISA surveys in Scotland.

Assessment sessions were conducted under standardised conditions, following detailed international guidance to ensure consistency across schools. This included guidance on test administration, timing, and support for pupils. Quality assurance processes were in place throughout delivery, including monitoring of test sessions and checks on data completeness and consistency.

2.2.1 The educational context for the PISA 2025 cohort

The pupils who took part in PISA 2025 experienced significant disruption to their education during the Coronavirus (COVID-19) pandemic. The 15 year olds who participated in the assessment were aged around 9 or 10 when the pandemic led to widespread school closures in 2020. In Scotland, most would have been in Primary 5 or Primary 6 when schools first closed in spring 2020, and in Primary 6 or Primary 7 during the further period of school closures in early 2021.

Although education continued during periods when school buildings were closed, pupils experienced substantial changes to how they learned, including a temporary shift to learning at home and greater reliance on digital technology. After schools reopened, pupils’ education continued to be affected by public health measures, including physical distancing, restrictions on school assemblies and other activities, class or year group “bubbles”, and periods of self-isolation following positive COVID-19 tests.

For many of these pupils, the pandemic also coincided with their transition from primary to secondary education. Restrictions affecting in-person transition activities remained in place until early 2022, meaning that some pupils had fewer opportunities than previous cohorts to visit their future secondary school and take part in the usual transition activities.

This is important context for understanding the educational experiences of the PISA 2025 cohort. The OECD has highlighted the COVID-19 pandemic as a major disruption to established ways of delivering education and as an example of how education systems can be required to adapt rapidly to unexpected change. The pupils assessed in PISA 2025 therefore experienced disruption during an important period of their schooling, followed by the transition into secondary education.

PISA cannot determine the extent to which these experiences affected pupils’ subsequent performance, and the results presented in this report should not be interpreted as measuring the impact of the COVID-19 pandemic. However, recognising the circumstances experienced by this cohort provides important context when considering their educational journey and the PISA 2025 findings.

2.3 Which other countries participate in PISA?

PISA 2025 includes 91 participating countries and economies: all 38 OECD member countries and 53 non-OECD countries and economies. Armenia, Dushanbe (Tajikistan), Ecuador, Kenya, the Kurdistan Region of Iraq, Rwanda and Zambia participated in PISA for the first time in 2025.

OECD member countries in PISA 2025

• Australia
• Austria
• Belgium
• Canada
• Chile
• Colombia
• Costa Rica
• Czechia
• Denmark
• Estonia
• Finland
• France
• Germany
• Greece
• Hungary
• Iceland
• Ireland
• Israel
• Italy
• Japan
• Korea
• Latvia
• Lithuania
• Luxembourg
• Mexico
• Netherlands
• New Zealand
• Norway
• Poland
• Portugal
• Slovak Republic
• Slovenia
• Spain
• Sweden
• Switzerland
• Türkiye
• United Kingdom
• United States

Partner countries and economies in PISA 2025

• Albania
• Argentina
• Armenia
• Azerbaijan
• Brazil
• Brunei Darussalam
• Bulgaria
• Cambodia
• China (People's Republic of)
• Hong Kong, China
• Macao, China
• Croatia
• Dominican Republic
• Ecuador
• Egypt
• El Salvador
• Georgia
• India
• Indonesia
• Kurdistan Region (Iraq)
• Jordan
• Kazakhstan
• Kenya
• Kosovo
• Kyrgyzstan
• Lebanon
• Malaysia
• Malta
• Mauritius
• Moldova (Republic of)
• Mongolia
• Montenegro
• Morocco
• North Macedonia (Republic of)
• Palestinian Authority
• Paraguay
• Peru
• Philippines
• Qatar
• Romania
• Rwanda
• Saudi Arabia
• Serbia
• Singapore
• Chinese Taipei
• Tajikistan (Dushanbe)
• Thailand
• Ukraine
• United Arab Emirates
• Uruguay
• Uzbekistan
• Viet Nam

2.4 How the study works

PISA does not test every pupil. Instead, it is based on a carefully designed sample. Schools and pupils are selected through an internationally specified sampling process, rather than being chosen by the Scottish Government.

PISA is an age-based rather than a year-group-based study. Eligible pupils are aged between 15 years 3 months and 16 years 2 months at the time of the assessment and have completed at least six years of formal schooling. Using a consistent age range allows pupils of a similar age to be compared internationally even where education systems are organised differently.

A two-stage sampling approach is used to select participants. First, schools with eligible 15 year old pupils are selected from across the country. Larger schools are more likely to be selected than smaller schools, reflecting the greater number of eligible pupils they contain. Schools are also grouped according to key characteristics, such as school type or location, to help ensure the final sample is representative of the national school population.

Once schools have been selected, pupils are chosen from within those schools. In schools with more eligible pupils than required, a random sample of pupils is selected. In schools with fewer eligible pupils, all eligible pupils take part. This approach ensures that the final sample provides a representative picture of the performance and experiences of 15 year olds across the country.

The assessment is completed on computer and typically lasts around two hours. Rather than completing a single test paper, pupils work through a series of short units containing different types of questions. These include multiple-choice questions as well as tasks that require pupils to write short or extended responses. Many of the questions are set in real-world contexts, such as interpreting scientific information, analysing data, or evaluating texts, reflecting the focus on applying knowledge rather than recalling facts.

Pupils do not all complete the same questions. Instead, each pupil is given a different combination of test units. This allows the study to cover a wide range of content and skills across the full assessment while keeping the experience manageable for individual pupils.

PISA introduced a multi-stage adaptive approach for reading in 2018 and mathematics in 2022. In 2025, this approach was extended to science. In computer-based testing, some later blocks of questions are selected according to pupils’ performance in earlier blocks. This helps to measure performance more precisely across the full range of pupil ability.

As such, PISA does not report results as a simple score such as “18 out of 30”. This is because pupils do not all answer the same questions, and some questions are more challenging than others. A simple total score would therefore not provide a meaningful basis for comparison.

Instead, PISA places each pupil on a scale of performance. This scale reflects how well a pupil has performed overall, taking account of the range and difficulty of the questions they have answered. Using a common scale allows results to be compared between pupils who may have answered different combinations of questions. It also supports comparisons to be made between countries and over time, as statistical linking allows results to be reported on a comparable scale across PISA cycles.

2.5 Background questionnaire

Following the assessment, pupils complete a questionnaire about their background, attitudes and learning experiences, which typically takes around 35 minutes. Headteachers also complete a questionnaire about their school, including information on resources, staffing and the learning environment.

The pupil questionnaire includes measures of socio-economic status and immigration background, which are used to help understand differences in performance.

PISA uses the OECD’s Index of Economic, Social and Cultural Status (ESCS) as its measure of socio-economic background. ESCS is derived from information provided by pupils through the background questionnaire, including parental education and occupation, and educational, cultural and material resources available in the home, such as books, study space and access to digital devices.

As part of the ESCS measure, PISA asks pupils about household possessions and resources. Some of these items are common across countries, while others are selected to reflect what is most relevant for measuring relative advantage and disadvantage in each national context. For Scotland, the household possession items included off-street parking, a guest room, a quiet place to study, a house security system, a subscription to TV or streaming services, domestic workers and a newspaper subscription. These items contribute to the international ESCS index alongside parental education and occupation.

ESCS is designed to support comparisons of socio-economic background across participating education systems. It is not directly comparable with the Scottish Index of Multiple Deprivation (SIMD). SIMD is an area-based measure of relative deprivation based on where a pupil lives, whereas ESCS is an individual-level measure derived from information reported by pupils about their family and home circumstances.

Throughout this report, ESCS is used to examine the relationship between socio-economic background and educational outcomes.

Immigration background is derived from pupils’ responses about their country of birth and that of their parents. Pupils are typically grouped into categories such as non-immigrant, second-generation immigrant (born in the UK but whose parents born elsewhere), and first-generation immigrant (born outside the country and whose parents were also born outside the country). These definitions are applied consistently across participating countries to support comparison.

2.6 Data quality and validation

Strict international procedures are followed throughout the PISA process to ensure that results are comparable. These include consistent approaches to sampling, careful translation of materials, and standardised administration of the assessment in schools.

Checks are carried out at both national and international levels to ensure the quality and reliability of PISA data. During and after data collection, responses are reviewed to identify any inconsistencies, missing data or irregularities.

At an international level, data submitted by each participating system are subject to validation by the OECD and its contractors. This includes checks on sampling, response rates, and the quality of assessment delivery. Where required, additional analysis is undertaken to assess non-response bias – that is, whether pupils or schools that did not participate differ systematically from those that did, in ways that could affect the results.

Although Scotland met the OECD participation standards for PISA 2025, a non-response bias analysis was undertaken as an additional quality assurance measure (see Annex A). This analysis found a similar pattern of non-response to that observed in PISA 2022 and did not identify any evidence that would prevent meaningful comparison with previous Scottish PISA cycles.

Only data that have been reviewed through the OECD’s international quality assurance and adjudication processes are included in the final international dataset. Where deviations from technical standards occur, the OECD considers the likely impact on data quality before determining whether results are suitable for international reporting.

PISA’s technical standards include requirements relating to the proportion of the target population covered by the study and the participation of sampled schools and pupils. The PISA-defined target population should cover at least 95% of the intended population; the weighted school response rate should normally be at least 85%, taking account of agreed replacement schools where appropriate; and the weighted pupil response rate should be at least 80%.

A small number of participating countries did not meet one or more of PISA’s technical standards relating to population coverage or school and pupil response rates. These were Canada, the Netherlands, New Zealand, Norway, Albania and the United States. The OECD assessed the potential impact of these issues and, where appropriate, applied additional reporting restrictions. Results for these countries are included in this report where available, but should be interpreted with additional caution.

2.7 Interpreting the results

PISA is based on a representative sample of pupils rather than testing every 15 year old in Scotland. The results are therefore estimates of what we would expect to see across the wider population of 15 year olds. Statistical methods are used to take account of this and to indicate how precise the estimates are.

2.7.1 Confidence intervals

All PISA results are subject to some uncertainty because they are based on a sample rather than the whole population. There is also uncertainty associated with measuring pupils’ performance using a limited selection of assessment questions. This uncertainty is expressed using confidence intervals.

A confidence interval gives a range of values around an estimate that is likely to contain the value for the wider population. In this report, 95% confidence intervals are used. This means that if the survey were repeated many times using the same approach, the confidence interval would be expected to contain the true population value in 95% of cases. Wider confidence intervals indicate greater uncertainty around an estimate, while narrower intervals indicate greater precision.

2.7.2 Statistical significance

A statistically significant difference is one that is unlikely to have occurred as a result of the uncertainty associated with estimating performance from a sample of pupils and a sample of assessment questions. In this report, statistical significance generally means there is a difference that is unlikely to be explained by statistical uncertainty alone, at the 5% significance level.

If a difference is not statistically significant, results are described as being similar. This does not necessarily mean that the underlying results are exactly the same; rather, there is insufficient evidence to conclude that a difference exists.

2.7.3 Mean scores

The mean PISA score is the average performance of pupils in a country or group. It provides a useful summary measure but does not tell the whole story.

PISA scores are points on a statistical scale rather than marks or percentages and do not have a direct meaning in the way that physical units do. A difference of 10 PISA points, for example, should not be interpreted as a 10% difference in performance. The meaning of differences in scores is better understood alongside proficiency levels and comparisons with other countries or previous PISA cycles.

For example, two countries may have similar average scores while having very different proportions of high performing and low performing pupils. For this reason, this report also considers the distribution of performance across proficiency levels.

2.7.4 Proficiency levels

PISA groups pupils into proficiency levels according to the knowledge and skills they demonstrate in reading, mathematics and science.

Particular attention is often given to the proportion of pupils performing below Level 2, which the OECD regards as a baseline level of proficiency, and those performing at Level 5 or above, who are considered high performers.

Each proficiency level describes the types of tasks that pupils can typically complete and provides a more detailed picture of performance than average scores alone. The score point ranges covered by proficiency levels differ between subjects, so proficiency levels should be interpreted using the descriptions provided for each assessment domain rather than as fixed increments on the PISA scale.

2.7.5 Trend comparisons and linking error

One of PISA’s strengths is that it allows performance to be compared over time. However, trend comparisons are subject to additional uncertainty because different survey cycles use different assessment materials.

To maintain comparability, some assessment items are carried forward between cycles and statistical methods are used to place results on a common scale. The uncertainty associated with this process is known as linking error.

Link error reflects uncertainty about whether scores from different survey cycles are directly comparable. It is considered in addition to the statistical uncertainty around the estimates themselves when assessing whether changes over time are statistically significant. As a result, apparent increases or decreases in performance may not always represent genuine changes once this additional uncertainty has been considered.

2.7.6 Plausible values

Unlike many examinations, PISA does not calculate scores directly from the number of questions answered correctly. Instead, each pupil completes only part of the overall assessment and statistical models are used to estimate achievement.

PISA uses a technique known as plausible values to represent a range of possible levels of achievement that are consistent with each pupil’s responses and other information available in the study. These values are designed to produce reliable estimates for populations and groups of pupils rather than precise scores for individual pupils. PISA scores should therefore be interpreted as estimates of performance at population or group level rather than as individual examination scores.

2.7.7 OECD average

Throughout this report, Scotland’s performance is compared with the OECD average. The OECD average is the arithmetic mean of the estimates for OECD member countries included in the particular comparison. Each country contributes equally to the average, regardless of the size of its population.

The countries contributing to the OECD average can vary for some indicators where data are unavailable. For comparisons over time, a consistent group of OECD countries may also be used so that changes in the average are not caused simply by countries entering or leaving the comparison. Where a restricted OECD average is used, this is identified in the relevant table or figure.

The OECD average does not include non-OECD countries and economies that participate in PISA. Results for non-OECD participants may nevertheless be shown in international tables and figures and compared individually with Scotland; they do not contribute to the OECD average.

2.7.8 Rounding

Figures in this report are generally rounded for presentation. As a result, percentages shown in a table or figure may not always add to exactly 100%, and differences calculated from the displayed figures may differ slightly from reported differences. Statistical tests and calculations are based on the underlying unrounded values.

2.7.9 Interpreting school questionnaire results

Headteachers of participating schools complete a questionnaire about their school and learning environment. Results from this questionnaire are weighted according to the number of 15 year old pupils represented by each school. They should therefore be interpreted as describing the proportion of pupils attending schools whose headteachers reported a particular characteristic, rather than the proportion of schools or headteachers themselves.

2.7.10 Sex and gender

PISA collects information on pupils’ sex but does not collect information on gender identity. All analyses presented in this report are therefore based on pupils’ recorded sex. For readability, the terms boys and girls are used throughout the report in place of male pupils and female pupils.