Reader’s Guide

Data underlying the figures

The data tables are listed in Annex A and available on line.

Four symbols are used to denote missing data:


The category does not apply in the country concerned. Data are therefore missing.


There are too few observations or no observation to provide reliable estimates (i.e. there are fewer than 30 students or less than five schools with valid data).


Data are not available. These data were not submitted by the country or were collected but subsequently removed from the publication for technical reasons.


Data have been withdrawn or have not been collected at the request of the country concerned.

Country coverage

This publication features data on 64 countries and economies: 34 OECD countries (indicated in black in the figures) and 30 partner countries and economies (indicated in blue in the figures).

Calculating international averages

An OECD average was calculated for most indicators presented in this report. The OECD average corresponds to the arithmetic mean of the respective country estimates. Readers should therefore keep in mind that the term “OECD average” refers to the OECD countries included in the respective comparisons.

Rounding figures

Because of rounding, some figures in tables may not exactly add up to the totals. Totals, differences and averages are always calculated on the basis of exact numbers and are rounded only after calculation. All standard errors in this publication have been rounded to one or two decimal places. Where the value 0.00 is shown, this does not imply that the standard error is zero, but that it is smaller than 0.005.

Bolding of estimates

This report discusses only statistically significant differences or changes (statistical significance at the 5% level). These are denoted in darker colours in figures and in bold in tables.

Reporting student data

The report uses “15-year-olds” as shorthand for the PISA target population. PISA covers students who are aged between 15 years 3 months and 16 years 2 months at the time of assessment and who have completed at least 6 years of formal schooling, regardless of the type of institution in which they are enrolled and of whether they are in full-time or part-time education, of whether they attend academic or vocational programmes, and of whether they attend public or private schools or foreign schools within the country.

Indices used in this report

Some analyses in this report are based on synthetic indices. Indices from student and school questionnaires summarise information from several related questionnaire responses into a single global measure. The construction of the following indices is detailed in the PISA 2012 Technical Report (OECD, 2014):

  • Index of ability grouping between mathematics classes (also named in this report Index of ability grouping within schools)

  • Index of between-school horizontal stratification

  • Index of creative extracurricular activities

  • Index of mathematics anxiety

  • Index of mathematics interest

  • Index of mathematics-related extracurricular activities at school

  • Index of mathematics self-efficacy

  • Index of mathematics work ethic

  • Index of perseverance

  • Index of quality of physical infrastructure

  • Index of quality of schools’ educational resources

  • Index of school responsibility for curriculum and assessment

  • Index of school responsibility for resource allocation

  • Index of sense of belonging at school

  • Index of teacher morale

  • Index of teacher support

  • Index of teacher shortage

  • Index of vertical stratification

  • PISA index of economic, social and cultural status (ESCS)

In addition, one index used in Chapter 3 of this report was derived to describe school absenteeism of students (skip a day of school, skip some classes, arrive late for school):

  • Index of school attendance

Abbreviations used in this report

% dif.

Percentage-point difference


Standard error



% pts

Percentage points


PISA index of economic, social and cultural status

Further documentation

For further information on the PISA assessment instruments and the methods used in PISA, see the PISA 2012 Technical Report (OECD, 2014).


This report uses the OECD StatLinks service. Below each table and chart is a url leading to a corresponding ExcelTM workbook containing the underlying data. These urls are stable and will remain unchanged over time. In addition, readers of the e-books will be able to click directly on these links and the workbook will open in a separate window, if their Internet browser is open and running.

Note regarding Israel

The statistical data for Israel are supplied by and under the responsibility of the relevant Israeli authorities. The use of such data by the OECD is without prejudice to the status of the Golan Heights, East Jerusalem and Israeli settlements in the West Bank under the terms of international law.


OECD (2014), PISA 2012 Technical Report, PISA, OECD, Paris,