Opponents of the concept of publishing school league tables advised this week that parents would be confused and misled by such information. Instead, they expect parents to study ERO reports, search school websites, browse through newsletters, interview teachers, and generally undertake their own due diligence to find out whether schools are turning out “kids who have taken control of their own learning” rather than just focusing on “readin’, writin’ and ‘rithmetic”, as one school principal put it.

In a perfect world, parents might well conduct their own detailed research, but few are in a position to do so. Many make judgments on less than perfect information such as decile rating, hearsay and zoning – the existence or otherwise of a zone being a surefire guide to a school’s popularity.

Despite the lack of clear, easily accessible information, most parents do their best to get what they see as the best education for their children. Those with both means and motivation can decamp to a ‘good’ zone, find a way around the rules, or pay for a private education. Some move mountains to make their way into high-performing Catholic schools. One way or another, parents exercise what choice they can. In Porirua, for example, more than half the secondary students attend schools outside their region and not local secondary schools, which have dismal achievement levels.

Parents need accurate information as a base for these decisions, and encouragement to use it. And what about the students left behind at failing schools? As the chair of the Iwi Education Authority, Pem Bird, pointed out, league tables would make schools work harder because results would be explicit and transparent. Failing schools would have to shape up rather than stay shrouded in vague terms such as ‘in line with similar schools’.

Opening up productive discussion between schools on how to improve practices is one of many benefits of Australia’s well-used My School website, a compendium of detailed comparative data on 10,000 Australian schools. It includes ratings against comparable and neighbouring schools and the national average, and uses an index of socio-educational advantage to enable valid comparisons.

Julia Gillard, who shepherded My School into life, says the site “tells you as much about how schools are going as I know as Prime Minister, and I think that’s a wonderful thing. That means we’ve all got the same information.” It’s hard to argue with that.