schoolperformancetables

Detailed Documentation

National Single Indicator (NSI): Calculations and Methodology

Calculation Base Components

Key Stage 2

The following performance indicators are used from the DfE’s published Performance Tables data:

  • Progress Measure, comprising:
    • Percentage of pupils making at least 2 levels of progress in Mathematics Test
    • Percentage of pupils making at least 2 levels of progress in Reading Test
    • Percentage of pupils making at least 2 levels of progress in Writing Teacher Assessment
  • Percentage of pupils achieving Level 4 or above in Reading and Mathematics Tests and Writing Teacher Assessment
  • Average Point Score
  • Overall Value-Added Measure

 

Key Stage 4

The following performance indicators are used from the DfE’s published Performance Tables data:

  • Progress Measure, comprising:
    • Percentage of pupils at the end of Key Stage 4 achieving the expected level of progress between Key Stage 2 and GCSE English
    • Percentage of pupils at the end of Key Stage 4 achieving the expected level of progress between Key Stage 2 and GCSE Mathematics
  • Percentage of pupils achieving 5 or more A*-C (or equivalents) including A*-C in both English and Mathematics GCSEs
  • Value Added Measure based on the best 8 GCSE and equivalent results
  • Total Average (Capped) Point Score per Pupil

 

Calculation Methodology

Exceptions

The following Exception Classes (i.e. no NSI Score is calculated or provided) are allocated:

Circumstances

NSI Exception Class Description

New School: no result data is provided in the Performance Tables

Unclassified - New School

School without data in one or more of the measures: will normally be either an independent school or a school with very small cohort numbers.

Unclassified - Insufficient Data

Special School: schools where all (or the vast majority) of pupils have special educational needs cannot fairly be compared to mainstream schools.

Unclassified - Special School

 

Generic Methodology

For schools not allocated an exception class, the following general methodology is used for both Key Stage 2 and Key Stage 4.

Step

Methodology Description

1

Calculate Standardised Scores
Each of the performance measures is standardised to provide a score between 0 and 1.

2

Allocate Weightings
For the purposes of calculating the NSI each of the 4 main performance measures are given equal weighting. For the component measures of the main Progress Measure equal weighting has been given between English and Mathematics.

3

Calculate Single Indicator Score
An NSI Score is calculated by multiplying each standardised score by its respective weighting and then dividing by the sum of the weightings (4 for the NSI).

4

Calculate Single Indicator Band
The mean and standard deviation of valid NSI Scores are determined. An NSI Band is allocated depending on the number of standard deviations from the mean of each individual NSI Score.

5

Calculate Single Indicator Ranking within Band
For each Ranking, the Minimum and Maximum Scores are determined and, consequently, the Score Range. Each NSI Score is allocated an NSI Ranking within each NSI Band based on the difference between NSI Score and the Band’s Minimum Score and that difference’s proportion of the Score Range.

 

Final NSI Allocation

The final NSI is either     (a) an Exception Class; or
(b) NSI Band plus NSI Ranking.