slef-reflections on statistics


The Tragedy of Targets

I've started using the phrase "tragedy of targets" recently for those situations where someone does something stupid to meet an ill-specified target, instead of working towards the result in the way the target-setter expected.

North Somerset Rubbish Targets

2007-07-11 (Permalink): One of my examples to explain "the tragedy of targets" used to be councils meeting recycling collection targets by collecting the recyclable waste, then putting it in landfill because that was cheaper than actually recycling it. That's bad because it makes a lot of extra work for everyone, but only meets the collection target in fact, not in spirit.

I stopped using that example because I thought it was too incredible and I didn't have a good reference to support it.

So imagine my surprise to see a report in the Weston Mercury saying:

"If Veolia does not have enough manpower it will send out a green waste lorry, or a domestic refuse lorry which usually picks up black bag rubbish, to pick up both at the same time. [...] The staff will just take it for granted that green waste is in the green lorries and domestic waste is in the blue lorries."

This is bad on many levels, even worse than my old example where recycling-ready waste was knowingly tipped into landfill. There's green waste contamination and false collection statistics, for starters.

The article continues to report that Cllr Carl Francis-Pester, North Somerset Council's executive member for environment, said:

"We are carrying out an immediate investigation into these allegations which we take very seriously indeed. This investigation will include urgent discussions with the contractor to ensure they are fulfilling the contract we have with them in the correct manner."

There doesn't seem to be any information about this investigation on North Somerset Council's web site. And if Veolia have spotted a loop-hole in the contract, then what?

Even if they haven't, the council has to watch solely-profit-led contractors like hawks because if you give them a chance to cut costs (and therefore increase profits), they will try it. That is the hidden cost of outsourcing, not covered by the Best Value Indicators and other privatised council jargon.

Incredibly, the councillor continues with:

"Thanks to the residents of North Somerset we have increased our recycling rate from 20.5 per cent to 30.8 per cent in the last 12 months."

If the allegations are true, then no, we haven't, because the statistics would be as full of toxic rubbish as the green waste lorries.

Have private rubbish collectors been doing this elsewhere?

2007-07-17 (Permalink): A few small pieces of recycling news for me to recycle:

The Weston Mercury repeats that a Recycling review will be carried out as a result of "staff will just take it for granted that green waste is in the green lorries" allegations, but no new news.

Guardian: Fortnightly collections not always the answer, say MPs so hopefully that will discourage any more one-measurement-fits-all moves.

Centred on Cambridge, cam.misc posters are describing what really happens when your recycling gets missed

Meanwhile, the WWN reports about The £300K Mistake so I think some signs may need recycling. Come back Tea's - your town needs you!

2007-07-23 (Permalink): Both local papers are reporting that the council's investigations found nothing wrong but there's still nothing on North Somerset Council's web site. WWN: Reports that recyclable waste is being dumped in landfill sites have been rubbished by the council. The Weston Mercury - News: Recycling gets clean bill of health

Police Targets

This gem was published by a Conservatives candidate over in my home county of Northamptonshire and was mentioned in today's Weston and Worle News

"an offender visited approximately 550 domestic properties in Weston-super-Mare with a fake comic relief sponsor form. This person obtained property by deception, (i.e. convinced them to part with money) from no less than 542 separate victims. Following good work from the police, he was caught, arrested, interviewed and I understand he will be cautioned for all the offences.

My sources tell me that as a result of the arrest, the North Somerset District was or is planning to claim 542 'detections' for this one job. This will prove to be an amazing result for the bean-counters and has no doubt salvaged the whole 'performance target' result for the area in 2006. Indeed, the local Police Community Support Officers have spent the week going door to door in an attempt to locate every household that was conned, and get them to sign a pro-forma statement of complaint to bolster the clear-up rate"

Do you know other examples where setting a target has had unintended effects? Do you have a suggestion how to set better targets for the police here? Me, I like the suggestion of one anonymous commenter:

"The Police should be measured on the absence of crime not by detecting it."

Scott Lamb commented:

"Measuring police on the absence of crime is even easier to game, with horrible consequences."

In more detail, Baruch wrote:

"The result of measuring absence of crime will be that reports of crime will be rejected if the cops will think that they won't be able to catch the criminals.

You will have to seperate the group that takes the reports and the group that handles them to make it work and even then I'm not sure someone won't find a way to go around that with another trick."

Well, if you read any cycling online forum, you'll have seen some reports of police rejecting reports of 'too hard' crimes like harassing cyclists. I think I've had one report accepted in the last year, about a moped user riding along a cycle track near a playground where I had noted the number plate, and two pretty certainly discarded. So, police discarding or discouraging reports of no-obvious-solution crimes seems to be happening already.

andy r wrote:

"Hi there,

Don't talk to me about tragedy of targets... As a teacher the word 'target' fills me with both fear and laughter.

Last year my year 6 class and I worked our butts off and achieved the highest set of grades for any school in North Somerset, thereby rescuing the school from a very sticky situation with Ofsted. Within days of these results being known the senior LEA advisor suggested to me that the targets had, perhaps, in hindsight been too low. My reply was curt and Anglo-Saxon. Hindsight! Looking out of her hind? The LEA love targets. If you hit them you have not pushed the kids enough. If you exceed them you should have pitched them higher. Woe betide anyone who fails to meet their targets (I will this year, different cohort and those % from last year have been INCREASED!)...

My kids have targets (though they have so many that they actually fail to remember them all). Teachers have targets for the numbers of children who are 'supposed' to achieve certain grades but the idiots who set them frequently have only a rudimentary grasp of mathematics. In my current school there are 45 children in a year group, so each one represents a little over 2%. In schools with small classes (perhaps 10 per year in some rural schools) 1 child can equate to 10%. If he's sick on exam day or is just not bright enough, that's 10% gone. And with the government expecting 75-80% of children to achieve a level 4 in their KS2 SATS, it's all too easy to drop blow your 'targets' through illness alone.

But here's an even worse tragedy of targets in primary schools... a couple of years ago I had to disapply 2 children from SATS, simply because they have profound special needs and could not take the tests. In addition, the school had an Autistim Unit (now called something PC, but I forget what) which that year had 4 children in year 6. Therefore we had 6 children who could not take the exams. We filled in the paper work but were horrified when the results came in to discover that these children (who all had official exemption on disability grounds) were counted as having taken the test, even though they couldn't. For 'statistical' purposes these kids were classified as having scored zero! Out of a cohort of 36 children, 6 were classified as not having done a thing! The department of education acknowledged that this didn't help our statistics, but stated that it was their policy. In a school with a lot of very deprived kids this 16% scoring zero, added to a significant quanitity of under-achievers was enough to push us down to the bottom 100 primary schools nationally. You can only imagine how damaging that was for the school's reputation - parents took kids out, we were slated in the local press and had to fight like mad to justify our continued existence...

Targets... bah!

Hey, talking of which. The Health Trust has recently done a survey of local primary school children's weights and heights. In our day this sort of thing was compulsory. Not any more. Parents had to 'opt in' to the survey... And guess what? The parents of the largest kids refused to take part - as did the ignorant b*strds, but that's another story. So the WAHT will now be collating a totally skewed data set. I'm just waiting for the press release highlighting our slim North Somerset children... And of course, someone will be complemented on achieving targets for reducing childhood obesity, whilst infact the problem has probably - as it were- grown.

I used to like the way that 'on time targets' were displayed in Didcot railway station. There was a board in foyer which highilighed punctuality. The impressive looking bar chart had these words written on it: "% of trains on time, compared to last month."

And the brightly coloured chart was always up around 95%, ish.

I was always suprised that nobody commented on that.

0.95*0.95*0.95...... month on month those trains were getting less and less punctual! But nobody bothered to point this out because 95% looks impressive! On many occasions I took the time to read, and re-read, the wording of those graphs so I know with 100% confidence that this was what they quoted. We never had a month with more than 100% punctuality compared to the previous month. Shame.

That's enough. I'm off to the dog house."

Bill Hay wrote:

"You think this is bad. At least they're only counting crimes he did commit. IIRC the police have been known to get captured criminals to confess to additional crimes they didn't commit in exchange for a recommendation of leniency. Helps the clear up rate no end."


Web searchers: Your Questions Answered

Totally unoriginal, but I thought it was amusing. I also get some strange search phrases:

"My gas meter is making a clicking noise" - then stop using the computer and call your gas company! (In England, the contact number should be on a label on the meter, or in most phone books under "Gas".)

"My computer is making loud ticking noise" - that's better. Open the case and listen to the fans and hard disks. One is probably broken.

"How many cars are there on the roads today" - too damn many?

"How to send an email so that everyone doesn t see the addresses" - put yourself in the To line and everyone else in the Bcc (blind carbon copy). See my email guide for other handy tips.

"How do i say in an email that there is an attachment" - How about "There is an attachment"?

"Samsung yp-u2 linux" - it works as long as you don't want to upgrade the firmware. More...

"How to satellite aiming motor europa" - point it at the sky, not at europa. I'll add more instructions to my satellite page as I rebuild my system.

"MJ bad" - at least there are 4 times as many "good" searches.

"How do I get the software for the samsung ml-4500" and "Samsung ml-4500 xp drivers" - I have a Ghostscript driver patch. Does Ghostscript work as a printer driver on XP?

"Cycle tracks near sandringham" - there's part of NCN1 alongside the A149, but most of the other cycle routes near Sandringham are along quiet roads (which is fine).

"What does wag stand for regarding football?" - Wives And Girlfriends. BTW it's a stupid TLA IMO.

"Wretton planning", "Wretton parish council", "business properties for sale in Wretton" and "properties for sale in field lane Wretton" - I've not been to Wretton in some time, let alone mentioned its planning or set up an estate agent there!

"How to grow grapevine in a conservatory?" - damned if I know. I would think the temperature change each time you open a door would hurt it too much.

"Hanging washing out over night" - it's a bad idea if it's going to freeze.

"Why some people take so long to reply to emails" - we're busy trying to thaw the washing out.

"Satellite frequency for ulster tv for sky plus box" - 10906MHz Vertical polarisation 22Msym/s, but can you record "other channels" on Sky Plus or should you buy a real DVR?

"Where can i find a picture of st james swimming pool in kings lynn?" - try Norlink's Picture Norfolk section.

"What happened to opensource.org?" - It was transferred from SPI to OSI. Strangely, the next search phrase listed was "simple example of unethical behaviour"...

"What to do about death?" - be very still and start to rot?

"bf uk cbhf" - I give up. Did 8 of you headbutt the keyboard?

"I hate belkin" - Me too.

"Interesting questions to ask someone" - no, not on this site.

"Bar" - best idea yet. Cheers!

Comments are moderated (damn spammers) but almost anything sensible gets approved (albeit eventually). If you give a web address, I'll link it. I won't publish your email address unless you ask me to, but I'll email you a link when the comment is posted, or the reason why it's not posted.

This is copyright 2007 MJ Ray. See fuller notice on front page.