Tip of the icecube
The Dominion-Post is reporting ‘hundreds of unfit teachers in class’. They haven’t made any attempt to scale this by the number of teachers, or compare it to other professions, or basically anything that would make the number interpretable.
The number of teachers employed at State or State Integrated schools in NZ as at April 2011 was 52460. This misses out the non-integrated private schools, but they are a small fraction (4% of students). With 664 complaints over two years, that is a rate of 1 complaint per 158 teachers per year. About half the complaints are dismissed.
For comparison we need other professions where the public can make complaints to independent adjudicators.
- As of June 2008 there were 8230 sworn members of the police force in NZ. In the most recent single year where data are available (2010/11), there were 2052 complaints to the Independent Police Conduct Authority, that is, 1 complaint per 4 police per year. Half the complaints were Category 5, ie, minor, too late, or otherwise not worth proceeding with.
- As of the last Census, there were 4284 people in NZ employed as reporters, editors, or sub-editors. This probably overstates the number of journalists relevant to the Press Council, since it includes technical editors, book editors and so on. The Press Council received 149 complaints in 2010, the last year for which they have published a report. In that year, 65 complaints went to adjudication (1 complaint per 66 journalists per year), and about half of these were upheld.
In all three professions roughly half the formal complaints that make it to the independent adjudicators are upheld and half are dismissed, but journalists are twice as likely as teachers to receive formal complaints, and police are about forty times more likely.
It’s quite likely that the headline is literally true: there probably are hundreds of unfit teachers, but that’s likely under 1% of all teachers. It’s worth trying to weed them out, but not without considering the costs. In any case, the amount of fainting and clutching of pearls the situations warrants is pretty limited.
Thomas Lumley (@tslumley) is Professor of Biostatistics at the University of Auckland. His research interests include semiparametric models, survey sampling, statistical computing, foundations of statistics, and whatever methodological problems his medical collaborators come up with. He also blogs at Biased and Inefficient See all posts by Thomas Lumley »