Attainment data in the performance tables

Each year the Department for Education (DfE) collects administrative data on pupils and their test, teacher assessment or exam results at each key stage. The data is collected from different sources and then matched together to create records of primary, secondary and 16 to 18 attainment for pupils, schools/colleges, local authorities and England as a whole. This data is then published at school/college, local authority and national level in performance tables. The process is illustrated in the process flowchart at the end of this page.

Where does attainment data come from?

Schools/local authorities (LAs):

  • School census – this is a statutory termly data collection, during which schools/LAs send the department details of the pupils they have on their roll and their characteristics. Characteristics data includes aspects such as gender, ethnicity and whether or not a pupil is eligible for Free School Meals.
  • Key stage 1 results - state-funded schools are required to report teacher assessments to their LA and the LA must then pass these results to the department. Note: key stage 1 results are not published for schools in performance tables but the data is used as part of key stage 1 – 2 progress measures.
  • Key stage 2 teacher assessments results – teacher assessments are collected from schools and local authorities by the Standards and Testing Agency (STA), an executive agency of the department. This data is shared with the department.

Key stage 2 national curriculum test results – state funded schools must register all pupils approaching the end of key stage 2 for national curriculum tests. Results of these externally-marked tests are provided to the department by the STA.

Awarding Organisations (AOs) – these organisations deliver regulated qualifications and award examination results to pupils and students at key stage 4 and 16 to 18. Each year, the department collects data from AOs, via an external contractor, on the pupils who have entered exams and their results.

How are performance measures calculated?

The data collected through the school census is matched with the relevant test, teacher assessment or exam results at each key stage to give a single record of attainment and characteristics for each pupil/student. These underlying records are then used to calculate performance measures for each pupil/student. For example, each key stage 4 pupil’s underlying qualifications and results are analysed to see whether or not they have achieved 5+ A*-C including English and maths GCSEs.

These pupil level performance measures are then aggregated to give the overall results for schools, colleges, local authorities, regions and England as a whole.

How does the department ensure the published data is accurate and reliable?

The department applies detailed checks and quality assurance processes to the data published in performance tables, ensuring we publish accurate and reliable data down to individual school and college level. Attainment data is validated at all stages of the assessment, collection and production process, to identify and correct missing or inaccurate information prior to publication.

Accuracy of assessments: The validity of assessment, test and exam results is assured in a number of ways. At key stage 2, a sample of schools are externally moderated to validate that teacher assessments are accurate and consistent with national standards. STA provides guidance on how schools must administer key stage 2 tests and LAs make unannounced monitoring visits to a sample of schools, to check that the guidance is being upheld. At key stage 4 and 16 to 18, exams are marked externally by AOs and Ofqual (a non-ministerial department) is responsible for monitoring that exams are delivered successfully and that GCSE/A level grade boundaries are set accurately.

Data transfer: The management information systems that the department uses to collect school census and attainment data all contain validation rules to assess whether the data being submitted is accurate and has full coverage. If errors or issues are identified, these are passed back to the institution or body submitting the data, so that these are amended and the data re-submitted.

Data processing: The performance tables are subject to an annual ‘dry run’, during which the department conducts a full run-through of the data production process using test data. The dry run is used to identify and correct any issues in the calculation of performance measures, in advance of ‘live’ data processing. Once the department receives real attainment data, further sets of validation checks are run to ensure that the data has been calculated accurately.

School checking exercise: The department shares attainment data with schools and colleges as part of a checking exercise. Each school/college can see only the data for their institution, giving them an opportunity to check that we have the correct results for their pupils and to highlight any amendments that are required. All amendment requests are scrutinised, to ensure that the changes are permitted. For example, pupils cannot be removed from the data and grades cannot be changed without an approved reason and valid evidence. Users can find information about whether a school has checked its data on its individual school page in performance tables.

Updates to attainment data following publication

Provisional results

In 2015, the department published provisional results information for secondary schools, on a subset of headline performance measures. This information is updated with revised results in the full 2015 secondary performance tables.

Post errata period

Following the publication of performance tables, there is also a short ‘post errata’ period during which schools and colleges have another opportunity to request amendments to the data, such as grade changes due to late re-marks. This further improves the accuracy and coverage of the published data.

As in the school checking exercise, all post-errata amendment requests are scrutinised to ensure that they are permitted. If an amendment is approved, the website is updated shortly afterwards. We also publish the date that the update was made, so that users are aware of any changes to the data for individual schools. Once the post errata period has closed, the performance tables are finalised and no further changes are made to attainment data.

Please note: The full attainment datasets available in the download data section of the website are only updated once the post errata period has closed. Each dataset contains information that tells users when it was last updated.

Information on the size and impact of the updates made to attainment data will be published in due course.

Updates to other data following publication

Although no further changes are made to attainment data after the closure of the post errata period, the department updates certain parts of the website throughout the year so that users can access the latest information:

  • School details - information such as the school type, whether the school is open or closed and headteacher name is checked and updated on a monthly basis using data from Edubase, the department’s register of educational establishments. If any changes are made to school details, the ‘last update’ date will be amended on their website page.
  • Ofsted inspection outcome - school inspections take place throughout the year, so the department receives regular data from Ofsted on the latest inspection outcomes for state-funded schools in England. If any changes are made to data for individual schools, the ‘last update’ date will be amended on their website page.

Further details on the quality and methodology of attainment data

The department publishes a series of quality and methodology guides covering the administrative data used to produce the attainment statistics in performance tables. These guides describe the methodology used to calculate performance measures and provide information on the data sources, their coverage, their quality and how the data is validated and processed.

The Statement of Administrative Sources for Attainment Data sets out how the department collects, processes and quality assures the attainment data published in performance tables

The detailed guides for primary, secondary and 16 to 18 data can be found alongside the relevant 2014/15 Statistical First Releases at the following links:

Other administrative data collected by the Department for Education

The Department for Education uses administrative data to produce a range of other statistical publications.

If you would like to find out more about how the department uses administrative data sources for other statistical purposes and the policies and procedures we apply to ensure data quality, see our Standards for Official Statistics page on This includes our ‘statistical policy statement on revisions’, which provides further details on why we make revisions to statistics, the process for making revisions and examples of how planned revisions apply.

Process flowchart