Why shouldn't parents rate schools?

What does Christine Blower, the general secretary of the National Union of Teachers, do when she wants to book a hotel? Presumably given her comments today on Ofsted's new Parent View website, Ms Blower completely ignores Trip Advisor and the ratings on other booking websites posted by those who have stayed there. Her reason: they are too 'subjective'.

Ofsted's site will give parents the chance to rate their children's schools on issues such as standards of teaching and behaviour, but also on happiness and the levels of communication with parents. Now, I may be mistaken here, but isn't such a rounded view precisely what the NUT has been demanding for ages? Indeed, one might have more sympathy with their objections to the site if they were staunch advocates of objective measurement of schools. But they have opposed testing and league tables since their inception, and I can't remember them ever being enthusiastic fans of independent inspections either.

The new Parent View site may take a little time to gain the level of parental input to make its judgements valuable. There may be the occasional problem if a school faces a determined campaign against it. But, as outstanding schools are no longer to be inspected, the site could alert inspectors to potential problems: if they investigate and find otherwise, it is better than not knowing of a problem until it is too late for many pupils. And in a world where people do want to see the views of other service users, the site also has the potential to offer an additional valuable perspective for parents interested in the quality of local schools.