The Writing Disadvantage

Is the attainment gap between disadvantaged and non-disadvantaged pupils bigger or smaller for writing than for maths or reading?

The disadvantage gap index summarises the attainment gap between disadvantaged pupils and all other pupils. A gap of zero would indicate that there is no difference between the average performance of disadvantaged and non-disadvantaged pupils.

The index is calculated by ordering all pupils’ point scores and deriving a mean rank for all disadvantaged pupils and a mean rank for all non-disadvantaged pupils. The difference between the two mean ranks is then multiplied by 20 for ease of interpretation.

The advantage of an index based on ranks over other measures of disadvantage is that it can be used to make comparisons between assessments that are on different scales. In England it is used at Key Stage 2 for Reading and Maths as both are assessed in Year 6 with external tests. The index cannot be used nationally for Writing, however, as it is only assessed with 3 grades, so the ranks of pupils would not be informative.

When you assess writing with Comparative Judgement, however, you can scale pupils’ writing performance to a level of granularity that allows you to calculate the disadvantage index. We can therefore compare the disadvantage index for writing with reading and maths.

Using a sample of 250 schools who have taken the writing assessments every year in February of Year 6 for the last four years we can see that the disadvantage gap in February 2023 was 2.81, up from 2.28 in February 2019.

The index for reading and maths was 3.21 in 2022-2023. The comparison suggests, therefore, that the average gap in the performance of disadvantaged and non-disadvantaged pupils is lower in writing than in reading and maths. In line with reading and maths we see a post-pandemic increase in the gap.

Caveats

Firstly, it should be noted that our analysis is based on a sample of around 10,000 pupils’ writing, so there could be a sampling effect. A larger sample of nearly 1,000 schools who took part in 2022-2023 only suggests a similar value, so this would seem unlikely. Secondly, while Comparative Judgement is more reliable than any other method of assessing writing, it is still less reliable than the objective tests of reading and mathematics, so the lower reliability may underestimate the index.