Schooling in statistical illiteracy

It is grimly ironic that the long-running debates in the media about university fees, school league tables and the relative merits of private education have been conducted through interpretations of statistical evidence which are riddled with the most elementary errors. On Monday 4 December, the Irish Independent published the figures for university enrolment in 2006, which revealed, once again, the class divide in education. Although only about 10 per cent of pupils attended fee-paying schools, they made up 25 per cent of university admissions.

This imbalance has been persistently used to argue for the re-introduction of third-level fees.  For example, in March 2006, the Independent summarised an OECD report which argued, “Fees are fairer since most benefits of third-level education accrue to the individual and most students come from higher-income backgrounds.” In August 2006, the Sunday Independent claimed. “The abolition of third-level fees has failed to increase access to university in economically-disadvantaged areas.” In order to assess such claims, it would be necessary to compare admission statistics in periods before and after the abolition of fees, something which none of these articles do. If they did, they would find that the exact opposite is true – university admissions have become less imbalanced since the abolition of fees.

Another area in which admission statistics have been mobilised is as a means of measuring the quality of schools. The article in the Independent which accompanied the figures for 2006 claimed that they proved that “parents who fork out heavily for second-level education increase their children's chances of getting into university”. Pupils at private schools are not a representative sample of the population – they are disproportionately wealthy and have a disproportionate lack of learning disabilities, amongst other sampling biases which render simplistic comparisons invalid. There is actually surprisingly little evidence to suggest that this section of the population would do any worse if they were sent to public schools.

School league tables rest on similarly shaky ground. The Sunday Times produces a ranking based upon the percentage of pupils in each school that gains entry to university. However, it is extremely difficult to say whether these figures are due to the quality of the education provided by the school, or whether they are simply down to the school's ability to select pupils who are likely to do well anyway. The Independent's ranking, based upon absolute numbers of university admissions, is even more obviously flawed.  Blackrock College is ranked at number four, while Jesus and Mary Secondary School in Salthill is ranked at number 25, despite the fact that a higher percentage of pupils from the latter gain access to university.

However, when it comes to abuse of university admission statistics, the winner of the gold star is an article which appeared in the Sunday Times on 5 November 2006, entitled “The brainiest children come from Ranelagh”. The fact that Ranelagh-based schools draw their pupils from a wide catchment area is just the most obvious reason among many why the article's headline claim is completely idiotic.