Primary IDSR – Key Stage 1 and 2 Diff No column

This series of articles will be looking at Ofsted’s Inspection Data Summary Report (IDSR).

In the previous article, we had a look at the Key Stage 1 and 2 attainment analysis in Ofsted’s Inspection Data Summary Report. However, there was one column that we didn’t look at: the “Diff no” column.

In this article, we’ll see what it is so important, using a Key Stage 1 example, and how it is used in conjunction with your Key Stage 1 Emerging, Expected and Exceeding cohorts.

Key Stage 1 and 2 – “Diff no” column

The remaining column is the “Diff no” column.

Taking the top line, we have the School’s figures of 88%, a National figure of 76%, and a “Diff no” of 6 – but 88 less 76 is not equal to 6. So, what is that Diff no column? It’s clearly not a percentage difference.

It is the difference in number of pupils – this school is 6 pupils above the National average. But how is that worked out?

Let’s take an example:

• Number of pupils: 46.
• School attainment: 76%.
• National attainment: 86%.
• Gap: -10%.

To calculate the difference in the number of pupils:

• You take the gap between your School and the National average – so in this fictious example, that’s minus 10% –
• Divide it by 100 and
• Multiply it by the number of pupils – in this case, 46.
• That gives us a number of pupils difference of 4.6.
• Then it is truncated it – removing everything after the decimal point.

What does this truncation mean?

• It’s good news if you are minus 0.9 pupils below – Ofsted will truncate that, and your school will therefore be in line with the National average.
• It’s not such good news if you are 0.9 pupils above, as that will also be truncated, and your school will be said to be in line with the National average.

Number of pupils, and Emerging, Expected and Exceeding

So we can read this column.

• This school is 6 pupils above the National average for the expected standard or above, and
• 9 pupils above the Greater Depth standard.

Looking at the other figures for the expected standard or above, this school is:

• in line for the Emerging cohort,
• 2 pupils above for Expected, and
• in line for Exceeding.

But 0 plus 2 plus 0 does not equals 6. So why is this school 6 pupils above for All pupils, but only 2 pupils for their consistent elements?

• Part of the reason is the truncation of the figures, and
• part is because some pupils do not have a EYFSP Prior Attainment.

However, the main reason is because this school, and presumably your school, does not have the national average of Emerging, Expected or Exceeding Prior Attainers from Early Years. So your average might be weighted towards the Exceeding Prior Attainment, as in the case with this school, or your average might be weighted more in terms with the Emerging.

So what can you do with this information? Well, let’s say that your school is above the National average for All pupils, but is in line or even below for Emerging, Expected and Exceeding. Is that going to cause you a problem?

For Key Stage 1 only, in the Ofsted School Inspection Update of November 2017, Ofsted said:

The EYFSP groups allow inspectors to reflect on a school’s approach to early literacy and numeracy, across early years, Year 1 and Year 2. This is not a value added measure, nor is it an accountability measure and should not be reported as an outcome. It is to inform inspectors and to prompt questions about the quality of teaching, learning and assessment.

So you can say to the Ofsted inspector, yes, we are in line or even below for Emerging, Expected and Exceeding, but you should not use these, as they are not an accountability measure, and you should look at the All pupils instead.

Example 2

But what if it was the other way round? What if you were above for Emerging, Expected and Exceeding, but you were below for All pupils. What do you do then? Well, the Ofsted Inspection Handbook says:

192. Inspectors will take particular account of the progress made by disadvantaged pupils from their starting points. They will consider the progress made by the end of the key stage compared with that made nationally by other pupils with similar starting points. …

For Key Stage 1 pupils, their starting point is Early Years. So, in this case, you could say: “Yes, I know we are 3 pupils below for All pupils, but you have to judge us on our progress that is being made – and the progress that is being made is quite good – it is in line with or above the national.”

Now, one can argue two completely different arguments with Ofsted. Please choose whichever argument is better for your school.

• If your school is above for all Pupils, then you could say that it is not an accountability measure.
• If your school is good for Emerging, Expected and Exceeding, then you could say that inspectors should take account of progress.

Finally, your disadvantaged pupils are being compared against National All and National Other, which is why the “Diff no” column has got two figures – a comparison against the National All, and against the National Other. For a discussion as to why your disadvantaged pupils are being compared against the National Other, please see our EYFSP article.

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In the next article in this series, we’ll be having a look at Key Stage 2 Progress.