MySchool - just how far behind can a school fall?

I've extracted some more data from the Chatswood and Fairfield areas regarding high schools, and applied it to my favourite graph - the one showing how the NAPLAN scores of schools improve over time. The problem with this data is that it's not continuous - you have kids going from primary school to high school, so there is a break in the data between years 5 and 7. On top of that, NAPLAN testing hasn't been going long enough to follow the same set of kids from grade 3 all the way to grade 9. The results for years 3 and 5 are from a different set of kids from years 7 and 9.

No matter - we just have to work with what we have.

The bottom axis is the ICSEA score - a measure of wealth. Poor areas to the left, rich areas to the right. The blue data points are the NAPLAN scores in year 3, the brown ones are the scores in year 5 etc etc. You can see how the NAPLAN results climb over time.

What surprised me is that the rich schools pull away in high school - particularly the state schools. There are a lot of very expensive independent schools on the North Shore, and the elite state schools leave them in the shade. More on that another time.

Have a look at the results of the school in the red circle. What you're looking at there is the NAPLAN score for a Fairfield school for its year 9 students. The long red line shows where it sits in relation to state schools in a rich area. By my reckoning, kids in year 9 at that poor school are at about the same level as kids in year 4 at the schools in the rich area. That's the difference between a state school in a good area and one in a bad area.

Antony Green and his take on the Greens

Green is always worth a read.

He rides a bike too - doubleplusgood.

More MySchool - just to annoy Cav

The theme for this evening is - chuck around a few hypotheses and see what sticks. I was always useless at defining a null hypothesis way back in my school days, so I'm not even going to try to do that now. I always buggered it up. I've spent the afternoon pulling down more stats and combining them to see what falls out.

Big caveat up front - this covers a limited number of primary schools in NSW. This is interesting stuff, but I'd need access to lots more data before staking my life on the results.

First idea - is there a relationship between the ratio of teachers to students and the amount of funding per student?

Answer seems to be "yes". I would expect that to be true since teacher's salaries are the biggest cost for schools. The R-squared is 0.688, making it a good fit. Part of the remaining variation could be explained by variations in mix of teacher salaries across schools - that is, one school might have 10 newbie teachers on $50k, and another might have 10 old farts on $80k. If they have the same number of students, the teacher/student ratio will be the same, but the second school will require funding 60% higher.

Just remember this - with state schools, over 80% of the bills are paid centrally. The schools never see much money - head office pays the staff, pays the maintenance bills, buys the computers etc etc. The numbers that have been released by ACARA are the result of the head office bureaucrats at the DET taking about $9 billion worth of expenditure and then trying to work out how to divvy it up between a few thousand schools.

I then split the stats for Catholic and state schools. Both show a very strong relationship between funding per head and student/teacher ratios.

However, we have to be careful when interpreting this - which is driving what? Remember, funding for schools is producer driven, not consumer driven. It's a chicken and egg question - does a school have a lower student/teacher ratio because it gets more funding, or does it get more funding because historically it had a low student/teacher ratio? Budget setting in the public sector is a strange beast - the amount of money you get can be based on the most illogical reasoning's at times.

Moving on - is there a relationship between the size of the school (number of students) and the NAPLAN scores? Is a small school better than a big school?

The graph above suggests that it makes no difference whatsoever. Big or small - doesn't matter. It might make a difference to the range of subjects you can study, but for NAPLAN results - zip.

However, I have coloured the data points to differentiate rich areas from poor areas. Blue are wealthy, brown are poor. There's a pretty clear split - the wealth and educational background of the parents counts an awful lot more.

Why do bureaucrats like big schools? Because it makes their life easier when dealing with a small number of big entities rather than a large number of small entities. They'll claim of course that bigness brings the benefits of scale, but the only things that I have ever seen scale well in a bureaucracy are stupidity, ineptness and bloodymindedness.

I then took the NAPLAN scores for a bunch of schools and looked at the performance of their grade 3 cohorts in 2008 and those same cohorts in grade 5 in 2010. I wanted to see how their scores improved over that period across a range of schools. Chatswood is a wealthy area - the average NAPLAN total went up 425 points. Why did some schools jump further than others? Has money anything to do with it?

Just to show you what I'm doing, here are 5 schools from Chatswood. The rhomboid at the bottom is their grade 3, 2008 NAPLAN score. The square up above is the NAPLAN score for that same class when it was tested in grade 5 in 2010. Along the bottom axis is funding per student. Did having more money produce a bigger jump in grades? It did for one school, but not the rest.

Here's the same schools, but with the data presented a different way. I've shown the student/teacher ratio on the bottom axis this time. The further a school is to the left, the better the student/teacher ratio (ie, supposedly smaller classes). The school with the biggest jump (in purple) had a low ratio (small classes) - however, the 2nd biggest jump was the blue school, which had a higher ratio. The rest were all the same - didn't matter if they had smaller classes or bigger classes, the improvement was the same.

The green school and the purple school both started at low NAPLAN scores, and both had small class sizes. The purple school leapfrogged ahead of two of the others with larger class sizes, but the green school didn't. Small class sizes might be beneficial - or they might not. Anyway - you need to crunch lots more than five schools to get an answer.

Which is what I did. I looked at how much the NAPLAN score went up for 70 schools, and then compared that to the student/teacher ratio. According to the R-squared, there is no relationship whatsoever. It's a paltry 0.03.

If you look at the percentage increase in NAPLAN scores vs the student/teacher ratio, you get a slightly better R-squared of 0.15, but this still means there is next to no relationship there at all.

I then split out the Catholics and the state schools, just to see if there was any difference. With the Micks, it's next to nothing.

State schools gets a slightly improved relationship, but an R-squared of 0.23 still means that there is two thirds of bugger all correlation.

Here's where things could get interesting. The blue dots are the grade 3 NAPLAN scores from 2008 for schools in a rich area and a poor area. Along the bottom axis is the ICSEA score - the measure of family wealth. There's a pretty clear pattern - schools in poor areas get much lower NAPLAN scores than schools in wealthy areas. The difference between the worst performing school and the best is 682 points - 1783 vs 2465. The schools in wealthy areas start out with an advantage of up to 38%. The difference between the averages across the two groups is about 14%.

The brown data points are the grade 5 NAPLAN scores two years later for those same schools. The same pattern appears - the rich schools stay ahead, but the average gap shrinks to 9%. Shockingly though, the lead of the best school over the worst stays at around 36%.

I've circled the lowest performing school from 2008.

Have a look at where its students get to by grade 5. Compare it to the schools in rich areas circled in green on the right. That green circle is the rich school scores from grade 3. For the grade 5 kids in the worst school in the poor area, when they hit grade 5, they are performing at the level of the worst performing rich area schools - from grade 3! Not only are they two years behind, but they're even at the back of that pack!

PS - remember, these are all state schools and low fee Catholic schools. What you're mainly seeing here is the difference in performance between a set of state schools in a rich area and a set of state schools in a poor area. In case you are wondering about funding, the poor state schools got an average of $9,498 each and the rich state schools got an average of $8,480 each - about a thousand bucks less (or the poor schools got 12% more). The best funded poor school got $10,894 - the lowest funded rich school got $7,057 (or the best funded poor school got 50% more than the worst funded rich school).

That rich school with the least money - only two schools out of this entire group got higher NAPLAN scores. The school with the highest NAPLAN score (in a rich area naturally) actually got the second lowest funding allocation out of all of them.

Anyway, that's just a taste of the sort of number crunching that can be done with these stats. ACARA, being a bunch of bastards, have made it as difficult as humanly possible to extract the numbers to do this sort of analysis, so it's both time consuming and shallow.

More posts on MySchool:

Number 6

Number 5

Number 4

Number 3

Number 2

Number 1

Damn, stuffed up teh numbering.

Number 0.

MySchool - why is it so?

Arguments regarding the amount of funding that different schools are getting are likely to rage on for the next 10 years. One statement that I read today was along the lines of, "State schools get less money per student because they are larger, and thus more cost effective". I thought I'd put that to the test by looking at the data from the Chatswood area - you make up your own mind.

First graph - size of school vs funding per student. The R-squared is 0.4 - not that crash hot. However, it does appear that larger schools get less funding per head - there is some relationship there. Just remember that correlation does not mean causation.

I decided to just look at State Schools alone - the R-squared drops dramatically to 0.28 - which means almost no correlation. This needs to be tested against a bigger data set, but so far, that idea is not looking good - at least in the state system. It could turn out to be an urban myth. Or more data might prove it.

But do we just care about cost, or is performance more important? I therefore decided to look at the NAPLAN scores for grade 3 vs the size of the school. When Catholic and State Schools are mixed there is almost no correlation whatsoever.

However, when you split them out, look at the difference. For Catholic schools, it appears that smaller schools deliver better NAPLAN results - the R-squared is 0.45, which is sort of reasonable but definitely not great. There is a weak correlation there.

But look at the state schools! The bigger the school, the better the results - and the R-squared is 0.7, which is pretty damned good.

Just remember one thing - this is looking at bugger all data. It's late, and I'm going to bed. I will crunch more numbers tomorrow and over the weekend.

1735099 - what's your opinion on this?

Thursday photos

It's been a week of early morning up and at 'ems for me - I haven't seen this many sunrises in a row for a long time. As usual, the clever 'lectric brain in the camera has made it seem much lighter than it actually was.

The blur of this jogger going past gives it away - the camera was open for a while and sucking in lots of light to get this shot. It's so dark, I had to stop to take shots - something I never, ever do. Except when it's nearly dark.

How glorious is that? Rowing into the sunrise. Except of course that none of the rowers can see it.

If it wasn't for the blasted trees, the view from here would be great.

If it wasn't for the blasted cars, the view from here would be great.

If it wasn't for the blasted cyclists riding through my shot, the view from here would be great.

This guy was a crack up. He was riding slowly and erratically through Pyrmont - I easily blasted past him. However, I heard him coming up behind me as I sat at a red light, and the bugger nearly crashed into me as he went careening past, half out of control. It was reasonably dark, and he had no light, not rear reflector and no helmet. When I went past, I found that he also had his headphones in, and was talking on the phone - I caught a blast of Arabic from him as I took off.

At least he kept his hands on the handlebars, and didn't wave them around.

I reckon he's a taxi driver that's lost his licence. He certainly cycled like many taxi drivers drive.

Jamie vs Verity

Another in my soon-to-end series on election posters. That's because the election is in 16 days, and after that, we hopefully won't see any more posters for a while.

Poor old Verity Firth can't win at anything. Whoever nailed up her posters has screwed up big time - they put a nail in the bottom and a nail in the middle - but not one in the top. That's meant that after a few weeks of rain and wind, many posters have folded in the middle and fallen over, completely obscuring the message. Here's an example.

That must be a metaphor for the hopeless Labor government - shoddy work that looks good initially, then falls apart after a short while.

According to the local rag, here are the centrebet odds on the candidates:

Balmain

Jamie Parker (Greentard) – $1.20
Verity Firth (Wife of junkie) – $4.50
James Falk (Boring normal dude) – $9

Marrickville

Fiona Byrne (Greenloon) – $1.22
Carmel Tebbutt (wife of Labor stooge) – $4
Rosanna Tyler (who?) – $9

Drummoyne

John Sidoti (Lib) – $1.22
Angelo Tsirekas (Lab) – $3.50

Strathfield

Virginia Judge (Lab) – $1.85
“John” Causcuscelli (Lib) – $1.85

Interestingly, the paper spells Labor as “Labour” and stuffed up the name of Charles Casuscelli. Guess they had the cadet reporter do that story. I know he's a wog with a tricky name, but even I can spell it correctly. Sheesh!

Wednesday photos

Believe me, it wasn't that bright when I took this photo - it is the magic trickery of the camera's innards that make it look like the sun was up. I had my headlight on and was dodgy around hard to see black dogs and so forth when I took this. Amazing what its little electronic brain can do.

I spotted this photo opportunity as I went past, and for once, I did a U-turn and went back and took the shot. Normally, I just blast on past if and ignore the lost opportunity. Onwards! Onwards.

You're probably wondering what I went back for....

That light is perfectly bisecting a coxless pair. You'd probably be able to see what I was on about if I had been riding with a proper SLR camera with say a 300mm lens. Ah well - at least I tried.

And even more election stuff

Got this in the letterbox this week - so now we know something about Alex Elliott, international man of mystery.

Even more election posters

Angela D'Amore still has her office going, even though she won't be the local member any more in 2 1/2 weeks time. That's not preventing her from using up her printing allowance in a misguided attempt to puff up her legacy. By April 1, people will be saying, "Angela Who?"

The alternative Angelo Tsirekas poster - the one that is not a leftover from a previous mayoral campaign. I don't get the use of slogans - "One of Us". What the hell does that mean? That he's not an alien from the Planet Zog?

Found this in a backstreet - almost fell of the bike when I saw it. It's the only one I've seen so far. Adam - here's a hint. Get a haircut before your next formal photo session. My motto is, "Never trust a Green in a suit". That goes for business suit, lounge suit or koala suit.

Ah, the missing poster from my last trawl - James Falk, the Liberal candidate for Balmain. We've heard very little about him in the media, because the media are obsessed with the battle between the Green and the Labortard. Poor old James gets no oxygen because he appears to be normal. My suggestion is that he takes drugs, crashes his car into a gay bar and then runs naked down the main street of Balmain with a flaming torch stuck up his bum. If he does that, he might cop a line in the local rag.

Tuesday photos

Sunrise this morning - beautiful time of the day to be up and about.

Seems it's not only cyclists that are carrying video cameras around with them to record idiot drivers - this motorcyclist appears to have one mounted on the side of his helmet.

Speaking of idiot drivers - see the black car up the road on the wrong side of the double white line? She shot straight up the road past all the cars (and me) waiting at the red light. I thought she was going to turn right into one of the buildings along the way, but she blithely drove all the way up to the intersection and was ready to continue through the light - until a bigger vehicle (the white van) came around the corner and just about smacked into her! After a bit of tooting, she sheepishly reversed back and ducked back across the double white line onto the correct side of the road.

At that point, I rode up through the traffic to have a look - just to confirm my prejudices. Yes, young female driver, doing her best to pretend it never happened. The video camera batteries were flat, so all I have is the photo of her being a right twat. Or should that be "moose claw"?

At last - a bicycle.

Now Libya gets interesting....

Is Egypt planning on grabbing part of oil-rich Libya?

Any Egyptian involvement in Libya has to be handled very carefully. While the two countries fought a three day war in 1977, the real cause of tension is the fact that for thousands of years, most of Libya was considered part of Egypt. Given the fact that Libya has all that oil, and less than a tenth of the population of Egypt, well, then, you can figure out the rest. But for the moment, everyone is a revolutionary brother. At least for as long as the moment lasts, then history takes over.

Go vote

Yes, go vote for your favourite election poster at Tizona's.

Remember, vote early, vote often.

Sorry, Cav

I didn't get any good photos of bikes today, so it's back to crunching numbers from MySchool again. Yes, I must be weird - I find doing a spot of number crunching to be quite soothing and engaging.

Tonight's exercise was to pick another area of Sydney and to bring in another 15 school's worth of data. I chose the Auburn-Granville area, which is probably best known as being the home of a bloody big mosque. Most of the suburbs in the area are on the poor side, so pulling them in just added another slab of green dots to the graph above.

However, one dot appeared up the top - I had a look into it, and found that I had included the state school at Newington. This is one of those new suburbs that popped up after the Olympics on the old Naval armoury near Homebush. It's a very nice, middle class area. Brand new, very shiny. It's no surprise then that it sticks out like a sore thumb compared to Auburn, and has results on par with rich areas like the lower north shore and the inner west.

I've stuck in three purple markers though - these are middle income suburbs, but their results are crap. I went back and had a look at the data - these places are probably well known to most Sydneysiders as the home of drive-by shootings and Muslim gangsters. So the residents there are doing OK economically, but living in a crime infested neighbourhood in the midst of lots of gangsters is not that great for the school results. As 1735099 commented, values and community has a lot to do with it.

So next time someone starts raving that public education needs wads more money, ask them if more money will buy a better set of values. If not, tell them to keep their filthy hands out of your pockets.

MySchool - education bang for your buck

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.