A post went up in the group this week asking a simple question: has anyone looked at their 'similar schools' section on the IDSR yet? It's new enough that half the room hadn't found it yet, and it matters enough that the other half already had views on it.
What it is
From September 2026, Ofsted's inspection data summary reports include a similar schools comparison for attainment. The DfE built a model that narrows a long list of possible factors down to the ones most strongly linked to variation in attainment between schools, then uses it to find your closest matches. It runs on whole-school pupil data rather than just the exam-year cohort, so it reflects your school's context, not one year group's results.
What it isn't
It doesn't feed into grading decisions. Ofsted has said this sits alongside the data already in your IDSR, as extra context for discussions with inspectors about achievement and progress, not a scorecard in its own right.
Where the worry in the thread actually sits
Several people pointed to the same tension: the comparison looks fine against this year's provisional data, but if your validated results land differently, that comparison shifts under you, without anything actually changing in what you've done. It's a fair worry. One member who'd been inspected that same week said the similar schools data had already come up as a significant part of the conversation with inspectors, so this is worth treating as live now rather than something to look at later.
A couple of people were also looking for it in the wrong place, checking attendance data rather than attainment. It sits inside the IDSR itself, not as a separate download. Someone in the thread shared the DfE's own explainer, worth reading before you go looking for it: Similar schools model for attainment: overview, GOV.UK.
Worth doing before your next inspection
Pull up your IDSR, find the similar schools list, and look at who's actually on it, not just where you sit against them. One head in the thread had gone further and visited a school ranked above them, to see what was different about their attendance practice. That's probably the most useful thing to do with this data: use it to find a specific school worth learning from, rather than just a number to worry about.
The DfE says a digital benchmarking platform is coming this autumn term too, which should make the comparison easier to check properly.
