They even do this on that skeptics' favourite, Mythbusters. The intro quotes the combined years of special effects experience of Jamie and Adam. At one point they even added up the years experience of the support team for good measure, but thankfully realised it was silly and stopped doing it.Originally Posted by Bunny
I suppose adding up years of experience almost makes sense, just like adding up the person-hours required to do a job -- though that does suppose, doubtfully, that N people doing a job get it done in 1/N of the time*. There has to be a better way to state it, though.
[* This might work in the old school maths problems like navvies digging a trench, but in collaborative ventures like programming the opposite is often the case: the time to get a given piece of code working goes up in proportion to the number of fingers in the pie.]
Should that be "the number of fingers in the 3.14159...."
The other one I love is "double the number of people ..." or "the number of incidents doubled" Double from what? From one to two or one million to two million?
Percentages of percentages is another favourite. Go from 10% of something to 15% of something and it becomes a 67% increase.
And now you've got me started, my wife can spend £200 in a half price sale and tell me she saved £200 today.
Another thought, why don't we add up the number of years skeptical experience on this forum and then claim this as authoritative when arguing with believers?
Shome mishtake shurely?
Well, now you have got me started, and I can tell you that a Scottish friend of mine used to run home behind a taxi, thereby saving far more money than when running home behind the bus.
When it comes to experience, isn't 100 years among a group of 5 people, say, a good thing? Especially with a subject only 20 years old and the experience of the individuals is not the same? It's got to be better than one person with 20 years experience, hasn't it? Or am I missing something?
The poijt beign that adding experience int his manner does not produce a meaningful result. Sure if you said 5 people each with 20 years of experience that'd tell you something.
Similarly if you were comparing a surgeon with ten years experience with a surgical team of seven with 2 years of experience each then you've got worthwhile infomration to go on.
However if all you were told was that one option comprised ten years of experience and the other 14 years of experience, then that information doens't necessarily help you pick the most accomplished option.
So you need to say who has got how much experience within a team, yes?
I mean that the sum total of years of experience in a team is, on it's own, a statistic for which there is no use that I'm aware of.
The maximum amount of experience of an individual within a team would be more meaningful.
Well done - and the correct answer is....?
Yes but you need to have that level of information. The point is that there seems to be a predilection in this age of marketing, only to give the "bottom line". Then the individual simply fills in the gaps, simply.
... fabulous medical breakthrough but it will take another five/ten/fifteen years before the ordinary Joe or Jane gets to see any of it -- you didn't think the researchers were about to work themselves out of a job, did you?
On the plus side, you're probably safe from a ticket since the speed cameras won't be able to catch you.
A similar complaint came up on the JREF forums recently, and as I pointed out there you have to be careful about how you correct this sort of thing. In that case it was about the effectiveness of an AIDs vaccine or something, which appears to reduce the chance of catching AIDs by something like 50%*. Of course, some people pointed out that it was only a very small risk in the first place so the 50% sounded misleading. That's a fair enough comment. However, they then went on to say that it would make more sense to say it was a 0.5%, since the actual risk went from 1% to 0.5%. But that's just plain wrong. No matter how misleading it can be to quote large percentage changes from a small absolute change, quoting the absolute change as a percentage is not just misleading, it's complete nonsensical.
There can be other problems with trying to pick holes in numbers. Take Bunny's example of saving £200 in a sale. Sure, if it's something you weren't going to buy otherwise, then you haven't actually saved anything. But if it's something you were going to have to buy anyway, you really have saved £200 by buying it in the sale.
It almost seems as if there's a backlash against statistics similar to the anti-PC movement that goes so far it becomes just as silly as the thing it opposes. Sometimes statistics and numbers can be used in a misleading way, but sometimes they're used absolutely correctly. It's important not to get the two mixed up.
That said, one thing that really bugs me is petrol stations ending all their prices with .9. Yes, research has shown that on average people really do think prices ending in .99 or .95 are cheaper and will buy them preferentially. But with petrol, there isn't anything to choose. Every single petrol station in the country uses the .9. And given that prices are currently well over £1 per litre, trying to pretend they're cheap is really a lost cause.
*Note that all numbers are made up for the example, I can't remember the exact figures.
Some shops have caught on to the fact that the £x.99 prices probably don't fool people any more and they would much rather have an easy way to work out exactly how much they are spending. The Fenwick department store near me has a lot of products at round number prices, at least in the kitchen department ... a coffee grinder for £20, not £19.99 for instance. I hope it catches on.
At the other extreme, some sellers seem to realise that everyone knows £x.99 prices are a con and so try to fool us with something like £x.89. The guy who recently quoted me for roof repairs clearly took a quick look at the problem from the other side of the road and thought "500 quid". He could have been honest and quoted £500, or he could have quoted £499 knowing I would realise he really meant £500, so he quoted £489 instead. I wasn't fooled by this either.
I completely agree. It is the deliberate or possibly ignorant misuse of statistics and numbers that I am complaining about.
I rememebr the BBC Radio-4 programme "Genius" where someone came up ith the idea of a 99 p coin. It had a slot in the side for a penny. With the penny, it was a pound coin and without it was a 99 p coin. Perhaps therefore we should have a 0.9 p coin?
You are wise to add this explanation as I have found to my cost several times on this forum. I am therefore going to take your lead and say the Radio-4 programm mentioned above was a comdy and the 99 p coin idea was a joke
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