Calling all education data nerds! Can anyone help me make sense of these slightly weird OFQUAL stats? (Comparing high grade GCSEs in grammar and private schools)

[clarexbp]

What do you make of these charts?

analytics.ofqual.gov.uk/apps/GCSE/CentreType/

They report % of kids scoring 7/A or above in GCSE in each of the main subjects, according to type of school attended.

Grammar schools (I'm presuming that's what they mean by 'Secondary Selective') and independent schools are neck and neck for most subjects (e.g. Biology, Chemistry, Classics, Computing, DT, Drama MFL, RS, to name a few). Curiously, however, for some subjects, there is a massive disparity, with grammar schools doing much better than independent schools.

E.g. in 2019:
Business Studies 30% v 49% getting A/7 or higher
English 31% v 48%
English Lit 38% v 54%
History 48% v 60%
Maths 31% v 65% (Wow!)

This looks like it's a consistent year-on-year pattern, not just an occasional anomaly.

Any ideas?

And you really need to remember that there are a lot of private schools that are not academically selective - eg there are a lot of Islamic/Jewish schools that are private, non selective and have very little attention paid to secular subjects.

I think you have made the same mistake Puffyisgood made, we know the statistics only include those who have entered GCSE. What we are saying is if the higher performing independent schools tend to sit IGCSEs, thus for those subjects aren’t included in the statistics, the independent school statistics are skewed towards the lower performing independent schools, therefore they will have lower results and aren’t comparable to selective state schools.

I don’t know about this specific data set, but normally independent SS are categorised as SS rather than independent for statistics purpose e.g. on the government school performance tables.

What we are saying is if the higher performing independent schools tend to sit IGCSEs

I have said that this sample is very small and there is no indication of whether it is representative. I don't know what proportion of higher performing independent schools sit IGCSE, but it is certainly clear that the ability spread in the sample in this dataset is far wider than that of the grammar schools in this dataset.

but normally independent SS are categorised as SS rather than independent for statistics purpose e.g. on the government school performance tables.

Yes but the classification here is self-reported, so may not be the same.

You posted I don't think it's about IGCSE because the data only includes centres which have entries in that subject group. which makes it sound like you thought we only suggested IGCSE may at least in part be a factor because we thought the data included IGCSEs. Hence my post, because that isn’t what we suggested.

I know it might not be the same which is why I posted I don’t know about this specific data set.

which makes it sound like you thought we only suggested IGCSE may at least in part be a factor because we thought the data included IGCSEs

The usual issue is that the data doesn't count IGCSE, so we end up with schools that take IGCSE scoring a 0% pass rate. As per the suggestions from the first few posters on this thread, which is what I was disagreeing with.

Well I was the first poster and I didn’t mean what you are suggesting and no where did I post that. When I posted I was well aware they weren’t counted at all and the results would be skewed towards the lower achieving independent schools as I posted in my follow up reply to LouisCatorze.

The difference could also be that selective schools e.g. grammars may not enter pupils for GCSEs if they are unlikely to achieve a good grade in a non core subject. This would affect History more than Maths / English where everyone would be entered.
Taking a GCSE subject in Maths a year early in Y10 e.g. Maths may also have an effect on the data as it would decrease the number of Y11 pupils achieving the grades which is recorded in the data.

*Reply to puffyisgood.

Not this data, it includes all students entered, regardless of age.

Oh yes, both good points. I bet they're at least part of the answer.

Will the independent school figures also include numbers from private exam centres that take elective home school students, and those doing resits perhaps? Might explain some of the discrepancy in English and Maths. I know my niece failed maths multiple times and ended up taking her GCSE in a private centre. Most of these students would be aiming for a basic pass, therefore diluting the stats? (The resit students, not necessarily EHE ones, although would be interested to know how they fare overall)