MEASURES
- Rate of teachers leaving the state-funded sector (attrition rate)
The number of full-time equivalent (FTE) teachers absent from the School Workforce Census (SWC) having been present in the previous census, presented as a proportion of the number of FTE teachers present in the previous census.
Attrition rates reported may differ from data reported by the Department for Education (DfE) due to methodological differences when cleaning the SWC data. Furthermore, attrition rates reported by the DfE account for only teachers with qualified teacher status (QTS), whereas we include both teachers with and without QTS.
Full-time equivalency adjusts every teacher in the census to the equivalent of a full-time teacher. For example, a part-time teacher that works 50% of a standard year would be classed as a 0.5 FTE teacher.
- Rate of early-career teachers leaving the state-funded sector (attrition rate)
The number of FTE early-career teachers (within five years of qualifying as a teacher), absent from the SWC having been present in the previous census, as a proportion of the number of FTE early-career teachers present in the previous census.
- Rate of teachers leaving their school (turnover)
The number of FTE teachers that are absent from the SWC or working in a different school, as a proportion of the number of FTE teachers present in the previous census.
- Net change in teacher numbers due to teachers moving school
The number of FTE teachers who moved school into the area/ school type, minus the number of teachers who moved school out of the area/ school type, as a proportion of the number of FTE teachers present in the previous census.
- Number of vacancies and temporarily filled posts per 100 teachers
The number of teacher vacancies (recorded as open when the SWC is collected in November) and the number of temporarily-filled teaching posts, as a proportion of the number of FTE teachers present in the census, adjusted to per 100 teachers.
- Average expenditure per pupil on supply teaching
School-level reported expenditure on supply teaching (category E02: ‘supply teaching staff’ in consistent financial reporting returns), divided by the number of pupils.
- Number of teacher trainees per teacher
Number of trainees enrolled in initial teacher training providers based in the area, divided by the number of teachers employed in schools in the same area. This measure does not capture trainees who are trained at a provider based in a particular area, but that may contribute to supplying other areas with new teachers.
- Number of trainees recruited to initial teacher training, as a proportion of the target
Number of trainees enrolled in initial teacher training programmes, as a proportion of the target required to meet the demand for new teachers (national only).
- Proportion of hours taught by teachers with a relevant degree
Number of hours of key stage 3-5 subject curriculum time taught by teachers with a relevant degree in that subject, as a proportion of the total number of hours of key stage 3-5 subject curriculum time. ‘Relevant degree’ is defined in the same way as the DfE qualification subject mapping (see Qualification subject mapping). We count non-teaching undergraduate degrees as relevant degrees, but not Bachelor of Education or Postgraduate Certificate in Education qualifications in the teaching of those subjects.
Due to a change in the data collection process for qualifications data, we do not present data from the 2015 census. Additionally, the DfE did not collect the qualification data in 2020, due to reducing the administrative burden on schools during the pandemic.
Since not all secondary schools provide curriculum data, the DfE uses a weighting methodology to adjust the measures that use curriculum data. This weighting applied, combined with the different methodological decisions made when cleaning the SWC data, may lead to differences to the measures as reported by the DfE.
- Proportion of science hours taught by teachers with different degree specialisms
Number of hours of key stage 3-5 science (physics, chemistry, biology or general science) curriculum time taught by teachers with a physics/ chemistry/ biology/ other non-relevant degree, as a proportion of the total number of hours of key stage 3-5 science curriculum time. ‘Relevant degrees’ for physics/ chemistry/ biology are defined in the same way as the DfE qualification subject mapping (see Qualification subject mapping). We count non-teaching undergraduate degrees as relevant degrees, but not Bachelor of Education or Postgraduate Certificate in Education qualifications in the teaching of those subjects.
Due to a change in the data collection process for qualifications data, we do not present data from the 2015 census. Additionally, the DfE did not collect the qualification data in 2020, due to reducing the administrative burden on schools during the pandemic.
Since not all secondary schools provide curriculum data, the DfE uses a weighting methodology to adjust the measures that use curriculum data. This weighting applied, combined with the different methodological decisions made when cleaning the SWC data, may lead to differences to the measures as reported by the DfE.
Adjustment made to subject-level measures
We made adjustments to the measurement method for some measures at subject level, to account for the number of hours taught per subject rather than FTE. Therefore, the following slightly different definitions apply to the subject-level analysis:
- Rate of teachers leaving the state-funded sector (attrition rate) at the subject-level
The total number of hours taught for the given subject by teachers absent from the SWC having been present in the previous census, presented as a proportion of the total number of hours taught for the given subject by teachers present in the previous census. - Rate of early-career teachers leaving the state-funded sector (attrition rate) at the subject-level
The total number of hours taught for the given subject by early-career teachers (within five years of qualifying as a teacher), absent from the SWC having been present in the previous census, as a proportion of the total number of hours taught for the given subject by early-career teachers present in the previous census. - Rate of teachers leaving their school (turnover) at the subject-level
The total number of hours taught for the given subject by teachers that are absent from the SWC or working in a different school, as a proportion of the total number of hours taught for the given subject by teachers present in the previous census.
In the SWC, a significant proportion of science teachers are identified as teaching combined science. These combined science hours are apportioned between the three component subjects based on the number of ‘known’ hours for the three subjects i.e. if 30% of the total hours taught in Biology, Chemistry and Physics is taught in Physics, then 30% of the total combined Science hours are attributed to Physics. This adjustment is used to calculate the attrition and turnover measures for the three component sciences. This has been defined using the same approach used by DfE in previous statistical analysis using the SWC (see DfE published: Analysis of teacher supply, retention and mobility).
The subject-level national average measures are based only on the sample of teachers for whom curriculum data is present.
Area definitions
- Local authority district areas.
Local administrative areas, as defined in April 2021. - Travel to work areas (TTWAs) TTWAs are a geography created to approximate local labour market areas: self-contained areas in which most people both live and work. The criteria for defining TTWAs are that at least 75% of the area's resident workforce work in the area and at least 75% of the people who work in the area also live in the area. The 2011 TTWAs were produced by Newcastle University, using an algorithm to identify commuting patterns from 2011 Census data. Some TTWAs overlap with country borders (e.g. England and Wales), but the teacher workforce data shown is only for the schools in England. More information on TTWAs is available on the ONS website.
- Parliamentary constituencies.
Electoral areas used for elections to the UK parliament. The areas are based on the areas used to elect MPs in the December 2019 general election and do not reflect any of the proposed changes made by the 2023 Review by the Boundary Commission for England
School type definitions
Pupil deprivation (eligibility for free school meals)
We categorise schools into five equal-sized groups according to the proportion of pupils eligible for free school meals in the January School Census for each year. These categories are defined separately for primary and secondary schools.
Education investment area
Education investment areas are local authority areas that have been identified by Government analysis as being areas where pupil outcomes at the end of both key stage 2 (KS2) and key stage 4 (KS4) are lowest. The areas were identified as part of the Government’s approach to ‘levelling up’, in order to target school improvement interventions in the parts of the country where performance at primary and secondary school is furthest behind. The details of the methodology for selecting these areas is outlined here.
Type of geographical area
We categorise travel to work areas (see above) into five area types for analysis. The groups are defined as follows:
- London
the London travel to work area (which includes some areas outside of London boroughs).
- Large urban areas
travel to work areas, excluding London, with a working population of more than 300,000 people. This group includes areas such as Manchester, Birmingham, Slough and Heathrow, and Reading.
- Medium sized areas
travel to work areas with a working population of between 300,000 and 150,000 people. This group includes areas such as Coventry, Oxford, Southend, Crewe and Tunbridge Wells.
- Small, non-coastal areas
travel to work areas with a working population of fewer than 150,000 people, and that are not next to the coast. This group includes areas such as Doncaster, Mansfield, Gloucester, Buxton and Hexham.
- Small, coastal areas
travel to work areas with a working population of fewer than 150,000 people, and that contain an area of coastline. This group includes areas such as: Blackpool, Eastbourne, Chichester, Bridport, Whitby.