OK, just to keep Cav sane, this is the last post with numbers and graphs and things for tonight. Normal bike bum service will resume tomorrow.
I have made up a new index - the number of funding dollars per student required to produce one NAPLAN point.
That is, if a school gets $8,000 in funding per student, and the NAPLAN score is 2,000, then it takes $4 to produce each NAPLAN point. The lower the number, the more effective a school is at turning our money into education (or at least the ability to do NAPLAN tests - the two are not necessarily the same). But just go with me for a minute.....
I then decided to compare the "BOAB index of educational efficiency" with the ICSEA score for each school. The ICSEA score tells you how wealthy the area is. Let's see how things went....
For starters, there's a pretty wide spread in scores, and the trend line gives us an R-squared of 0.55. Here's how I interpret this graph - the poorer the area, the more money it takes to provide an education. If you compare a rich area with a poor area, it can take nearly double the amount of money to provide the same outcome in the poor area.
Here's the same graph, with the axes set to zero. I don't want you thinking that I'm manipulating things by playing with the axes.
I then separated out the Catholic schools. The R-squared here is 0.0398 - in other words, there's bugger all correlation between the two variables. In Catholic-land, the wealth of an area has almost no impact on how much it costs the Micks to bash knowledge into poor kids and rich kids.
With state schools, it's an entirely different picture. The R-squared here is 0.69 - pretty bloody good in my books. You can also see a clear split between two sets of schools - an upper shoal and a lower shoal.
I've then colour coded the two groups. The red dots are all state schools in rich areas; the green dots are state schools in a poor area. Wow - the difference really stands out.
I've then broken the numbers out for the state schools and divided them into rich and poor zones. The R-squared for the poor group is 0.088 - it's rooted. However, a 5 order polynomial gets up to 0.6.
However, for the rich group, the R-squared is 0.59. By stuffing around with a 5 order polynomial, I got that up to 0.77.
But what does all this tell us?
When it comes to State Schools, it's clearly a two speed system (although I'll have to delve into some other areas that are middle income to see how they fare). There is a massive divide in performance and cost between the state schools in rich areas and the state schools in poor areas. And it has to be remembered that all that extra money in the poor areas isn't buying results - the state schools in rich areas clearly outperform the state schools in poor areas.
I've taken that graph again and coloured in the Catholic schools in orange. A strange colour for Catholics, I know. However, what it shows is that there isn't the same divide as you get in the state system.
What cracks me up about this is that the haters of non-state education love to say that private education creates a gulf between rich and poor. Well, perhaps it does - but the state system is no better. If anything, it might be worse. If you want to prove me wrong, go away and crunch the numbers and see what you can come up with. I went into this exercise with an open mind - I just wanted to throw some numbers around to see what came up. I have to say that I'm quite shocked at the results.