The media often quotes headline exam results to show the supposed superiority of private schools. However a fair comparison is only possible if the intakes are similar. Within the state sector comparisons can be made with value added figures, but these aren't available for private schools. It is interesting then to compare a school from each sector.
Wellington College is a highly regarded elite private school with an exam to gain entry. Its web site publishes
its exam results. Last year 75% of GCSE grades were A or A* (a record, up from 63% the previous year). For A levels, 66% were A or A*.
Stoke Newington School is a comprehensive school in Hackney (which I chair) with a wide range of students. There is no selection on entry and so it would be an amazing achievement to match the Wellington figures overall. However we can create a comparison by analysing the results of the most academic students within the school.
Those students who arrived at Stoke Newington School with a 5b or better in English , Maths and Science make up 8% of the intake. Among this group are the students who might have stood a chance of gaining entry to Wellington College. Tracking these students to GCSE last year, we find that 70% of their GCSE grades were A or A*, above the figure for Wellington.
The same is true of A level results. Taking the top 10%, by GCSE results two years ago, we find that 77% of their A level grades this year were A or A*. Again this is a little above the Wellington figure. So Stoke Newington School could be said to outperform Wellington College, when comparable groups of students are used.
Too often there is an assumption in the British media that private schools are somehow better. This is only one example, comparing two schools (though I chose Wellington because of its reputation for academic excellence), but it is perhaps an indication that with comparable intakes it isn't clear there is any better performance in the private sector.
Note: This analysis was prompted by this year's A level results. However inevitably most of the figures above are based on last year's results (as 2012 GCSEs aren't available yet and the Wellington College web site figures are still those for 2011 A levels). I will seek to update them once the full 2012 figures are available and published.