There is doubt. It’s widely understood that when dealing with human populations there is typically more variation within a group than between groups. For example, the average wage in NSW is higher than the average wage in Tasmania. Only a fool would extrapolate that everyone in NSW earns more than everyone in Tasmania, or would be surprised that the extrapolation is false.

“It is fair enough for education bureaucrats (for which the NAPLAN tests were designed) to ignore this local variability, but any parent that chooses School A because it did better than School B on the NAPLAN tests is likely to have her kid end up in a class that is worse than the class they would have ended up in School B. So much for parent choice.”

Is there any logical basis for this statement? School A has higher outcomes than School B - based on an imperfect comparison, but the only one we currently have - so if I choose School A then I am likely to have my child end up in a class that is ‘worse’ than their corresponding School B class. This is a non sequitur, as are your closing comments.

C-, must try harder.

Why is it obvious that Julia Gillard wants to be seen to be promoting such retrograde steps as school league tables?

Surely there is doubt. It could be as simple as a school having graded classes within the one year.

The article is correct that Professor Wu IS one of the few people who understands the complexities of statistics in educational measurement. League tables of schools based on forty multiple choice questions is simply invalid.

So let’s leave academic la-la land for a second:
Firstly, does this professor propose a better approach? If not, let’s go with the “bad” league tables.
Secondly, Professor who? I know a Prof who is apparently the leading Australian expert on sexual politics. Shall we seek her permission before we ask someone on a date? Pu-lease.