Methodology

The data in Ofsted: explore an area comes from several sources. Much of it is from other databases held by Ofsted but some data has been published by external organisations, and we have downloaded and processed this ourselves (see data sources). This methodology document will explain some of the processing that we do.

Attainment data

We use attainment data downloaded from the Department for Education (DfE)’s Explore education statistics. All these datasets are published annually, in the autumn term, but may be updated subsequently.

We present average local authority and national key stage 2 (primary) pupil attainment data for the following measures:

  • year 1 phonics: the number and percentage meeting the expected standard
  • multiplication tables check: number and percentage who scored full marks (25 marks)
  • key stage 2 reading, writing and maths: numbers and percentages meeting the expected standard and the higher standard
  • the total for all of the above, and the data by free school meals (FSM); English as an additional language (EAL); school special educational needs (SEN) support; education, health and care plan (EHCP); and total special educational needs and/or disabilities (SEND) (SEN support and EHCP) cohorts

We present the average local authority and national key stage 4 (secondary) pupil attainment for the following measures:

  • average Attainment 8 score
  • average Attainment 8 score for the FSM; school special educational needs (SEN) support; education, health and care plan (EHCP); and total special educational needs and/or disabilities (SEND) (SEN support and EHCP) cohorts

Due to the COVID pandemic, key stage 2 exams were cancelled in 2020 and 2021. These values are used as the baseline to calculate Progress 8. This means there are no Progress 8 values for key stage 4 attainment in 2025 and 2026. It is possible that Progress 8 will return for exams sat in 2027. For more information, see this document from the DfE (opens in new tab).

There may be some small discrepancies between published percentages and the values we calculate. This is because the DfE’s published data often rounds to one decimal place, while we store our data with five decimal places of precision. Someone rounding from the published values may round the wrong way if the percentage is near to 0.5.

Attendance data

These figures are derived from data automatically submitted to the DfE on a daily basis by participating schools. We use the DfE’s fortnightly publication that shows weekly attendance data.

We use the overall attendance of pupils in local authorities and nationally. We have also broken the data down by pupil characteristic, so SEN pupils combine school-provided SEN support and those with EHC plans. Where the data is aggregated, overall attendance is calculated as:

Equation shows attendance percent equals the sum of the number of sessions attended divided by the sum of the number of possible sessions

Children's obesity and overweight

We use data from the National Child Measurement Programme (NCMP) to show the percentage of children in reception class (aged 4 to 5 years) who are overweight or obese.

To avoid disclosure of sensitive information, the source publication aggregates City of London into Hackney and Isles of Scilly into Cornwall. We have marked these local authorities as having missing data.

The NCMP does not measure all children in a local authority. The prevalence figures are estimates based only on those children who were measured and should be interpreted with caution.

Elective home education data

We use elective home education (EHE) data downloaded from the Department of Education (DfE)’s Explore education statistics page. We present data on the number and rate of individuals in each local authority who are currently in EHE and further aggregated across key stage 2 (primary) and 3 (secondary).

All local authority data was rounded to the nearest ten. The data provided by the DfE contained both unavailable and suppressed data points. Suppressed data points are those that round to zero but are not in fact zero, in our analysis we treated these data points as zero and thus figures may not sum to breakdowns due to rounding. Unavailable data points were treated as NA throughout the analysis.

Early years funded education data

Two-year-olds

The estimated number of eligible 2-year-olds in this publication comes from data published by the Department for Work and Pensions each November. This is the best available measure of children meeting the benefit and tax credit criteria.

The number of disadvantaged 2-year-olds eligible for the entitlement has decreased, but take-up rates have increased. This is because eligibility has fallen faster than registrations, due to:

  • lower birth rates in recent years
  • the move from legacy benefits to Universal Credit
  • unchanged income thresholds while average incomes have risen

Even if the rate goes up, the fall in eligibility means fewer children overall are benefiting, so it is important to consider both the percentage and the number.

Three-year-olds

All 3-year-olds are eligible for funded places. Values over 100% are due to falling birth rates, which reduced the overall population more than the number registered for a place. A percentage above 100% shows very high take-up. In other words, more children are registered than the estimated population.

Early years oral health data

The data we have included is the number of children examined, the percentage of the total 5-year-old population that were examined, and the percentage of children that showed any sign of tooth decay.

Limitations and issues with the data

15% of upper tier local authorities did not commission the survey. City of London and Isles of Scilly did not meet the minimum sample size. More than three quarters of the local authority areas in the South East and approximately a third of the local authority areas in Yorkshire and The Humber did not participate in the survey and regional estimates for these areas should be interpreted with this in mind. For more information on the limitations of the survey, please refer to the publication (opens in new tab).

Income Deprivation Affecting Children Index (IDACI) data

The Income Deprivation Affecting Children Index (IDACI) measures how the income subdomain of the Index of Multiple Deprivation (IMD) specifically affects children aged 0 to 15 (under 16) in England. This most recent data became available with the 2025 IMD statistics.

IDACI is a ‘rate’, meaning that it is the proportion of children in an area that are income deprived.

These statistics are prepared at lower layer super output area (LSOA) level [footnote 1] and are intended to provide a high-resolution picture of deprivation across England. However, for Ofsted: explore an area, we want to prepare a dataset at middle layer super output area (MSOA) level [footnote 2].

1. Lower layer Super Output Areas (LSOAs) (opens in new tab) comprise between 400 and 1,200 households and have a usually resident population between 1,000 and 3,000 persons.

2. Middle layer Super Output Areas (MSOAs) (opens in new tab) are made up of groups of LSOAs, usually four or five. They comprise between 2,000 and 6,000 households and have a usually resident population between 5,000 and 15,000 persons.

How we aggregated the IDACI scores to MSOA

The research report (available here (opens in new tab)) describes the 2-step process to calculate the statistics for higher geographies:

  1. Sum the population-weighted scores from the 2021 LSOA geography to 2021 MSOA geography.
  2. Rank the resulting scores across the 2021 MSOAs.

We use the population-weighted scores from step 1 rather than the rank calculated in step 2. Because this is IDACI, we use the population of 0- to 15-year-olds to weight the scores.

Population weighting requires multiplying the score by the population of the LSOA then dividing by the aggregated MSOA population:

Image shows two equations. The first equations shows the weighted LSOA score equals the LSOA score times the LSOA population. The second equation shows the weighted MSOA score equals the sum of the weighted LSOA scores divided by the sum of the LSOA populations

Our full method is:

  1. Load the IDACI data and filter to only areas in England.
  2. Calculate the population-weighted average IDACI score in the 2021 LSOAs using the 2025 IDACI score and included 2022 population estimate data.
  3. Join the IDACI 2025 data from step 2 to the 2021 LSOA to MSOA lookup table (opens in a new tab) provided by the ONS.
  4. Join the combined IDACI and lookup data from step 3 to the 2022 MSOA population estimate data (available from NOMIS (opens in a new tab)).
  5. Calculate the population-weighted average IDACI score in the 2021 MSOAs using the 2021 LSOA IDACI scores and 202 population estimate data.

How we got a national IDACI score

There is no national IDACI score available, and the research report does not specify a method for aggregating to a national value. Instead, we calculated the mean of all IDACI scores across England to provide a single representative national figure.

Special educational needs and/or disabilities (SEND) data

Early years SEND

Where counts of SEN support are shown on the early years remit tab, these include pupils in all state-funded settings, including nursery, primary, and special schools.

SEND in schools

In all cases on the schools remit tab where there is a total special educational needs and/or disabilities (SEND) count, this is the sum of those with school SEN support or an EHC plan and that attend state-funded schools.

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