Thursday, 28 October 2010

Good grief

Hobbit madness ... so much backtracking: is the whole mess corrupt? First its not about money, but it seems money is what it took after all. There's a boycott, there's no boycott. The fallout is that contractors are no longer employees.

People involved with the copyright and acta stuff are not at all surprised to find NZ law being dictated by overseas corporate interests.

Also: Shrek the sheep has been a NZ icon - first I heard of it ... since when? And was this really big enough to spend so much air time on it? Probably I'm just watching too much TV.

Meanwhile - yesterday was my wedding anniversary :(

Saturday, 23 October 2010

Sunny Days

Labour Weekend is here - for non Kiwis, this is the time we celebrate employment and the work ethic by having a day off.

Waiheke is excruciatingly Sunny and more full of exciting people than a pomegranate is of pips - making it sound a lot like Ursa Minor Beta from Hitch Hikers. There are lots of tired parents and frazzled kids out too. Breakfast in the Sun today - pancakes, banana and bacon, with maple syrup.

I've had the first combined counseling last week - a bit of an ache to see Cathy again. She repeats her "we can still be friends" and I'm staying diplomatic. As time wears on I'll just get more used to not being married I guess. We'll have to see. So far I have not experienced any special interest in other members of the fair sex so who knows.

My phone lines are weird - been experiencing mysterious hang-up on voice as well as dialup. The tech has found a funny wire paring on my line, changed me to another one ... hopefully that is all there was to it. Meantime, Vodaphone's faultsperson has emailed a bunch of suggestions specific to MS Windows so I have send a bunch of technical specs back for my Unix-based system to see what they make of it. It can be frustrating when you know more about computers than the help team. BTW: their suggestion amounted to either switching the software on or reinstalling it.

Typical Windows mentality.

Monday, 18 October 2010

Paranormal Testing

"Enemies of Reason" (Dawkins and Clements 2007) shows an example test of claims of water dowsing. Strikingly, none of the dowsers tested were convinced that they were not doing anything special. (All failed the test.) This leads into one of my pet subjects:

There is a difference between being right and being convincing.

Conducting the test properly, you want to get the claimants to demonstrate their special power in the experimental setup to their own satisfaction. In the dowsing example, there were six rows of six buckets. In each row, one bucket had water and the others sand. Assistants placed the water in a random bucket and left the tent, the experimenter lead the claimants through each row and, in their own time, attempted to find the water. Thus it is double-blind and we expect roughly 1 in 6 of the attempts (across all dowsers - some won't get any and a few will get two.) to find the water. To demonstrate their powers, a dowsers must perform significantly over the odds ... considering not a single dowser claims less than 100% success rate, this should be easy.

Claimants consistently tested at odds, but this did not phase them. Each usually cited something about the presence of sceptics, nervousness, or that the setup was somehow throwing the detection off. One claimant protested that the water being above the ground and having to walk around the buckets was a problem.

The way to counter this is to do two tests - in the first you have to establish that nothing about the setup is having an adverse effect. In this case, in the first test, show the claimants where the water is and get them to verify that they can dowse for it successfully. (Our null hypothesis is usually that the dowsers somehow read clues as to where the water is, so we expect 100% detection rate this way.) This should be quite a quick test. Get the claimant on the record accepting the test setup for the double blind. Then conduct the double-blind version.

This can be presented in a freindly way, "just to make sure that your ability works in here". Between tests they need to be encouraged to express

We want to be careful not to test the double blind version as the "real" test, so as to avoid the possibility that the situation is psychically different or that there is added pressure. Even add the possibility that there is a third test upon "success" in the second, which is the "real" test. Once the double-blind results are in, repeat the first test to completely demonstrate that the conditions have not changed.

What we expect is that the dowser will have a 100% hit rate on the first test, chance on the second one (a fail), and another 100% on the third. Though a clever charlatan may make sure they have only odds on the third experiment, we don't normally see this. This is also why we do not want to actually endorse people who pass - but, instead, to move to a more detailed study. This is more difficult and usually means we have to catch the faker in the act.

Strictly speaking, performing at odds in the double-blind does not mean that the claimant is not doing anything supernatural, just that whatever they are doing is not distinguishable from guessing. Even with the above rigour, we still expect protests and anecdotal evidence to show that the experiment had to be wrong ... after all, the claimants are usually honest people who have become convinced of their powers over time. However, the protests will be all the weaker as a result of the rigour.

When observing tests conducted by others we need to keep our brains engaged. For example:

Movie: Beyond a Reasonable Doubt
Bar Doubt LLC 2008
Jesse Metcalfe, Amber Tamblyn, and Michael Douglas

Features a journalist (Metcalfe) conducting a test involving coffee tasting.
Members of the public are invited to blind-taste coffee from three urns. One instant, one canned, and one expensive brew. We are told that 57% of those tested reported that one of the two cheaper coffees was the better tasting. The journalist then announces that this means that the expensive brew is not all it's cracked up to be.

There are two things wrong with this test - the method is suspect because the test subjects are self selecting from a limited population (people passing on the street volunteer) and it is single-blind (the journalist stands over the subject). But more seriously, the results do not support the conclusion - one of the most damning critiques available to science.

If there was no difference between coffees then we'd expect the selection to be random. Two out of three choices are the cheap ones so we'd expect cheap brands to be chosen as best about 67% of the time. 57% is much less than that, suggesting that there may be something to this expensive coffee thing.

However, this does not reflect poorly on the logic of the film. It turns out that everything Metcalfe's character is invloved with is faked in some important way. This test then becomes a foreshadowing of later revelations. It actually strengthens the film. Unfortunately, few of the audience pick up on this and some come away with the impression that the concusions were correct even though they went in knowing they were about to watch a bit of fiction.

For movies it is reasonable to assume that everything you see is false, and I do mean everything. "Based on a true story" means "this is fiction" and the portrayal should not be given any more weight than something which is self-professed as entirely fictional. Documentaries are similar. By convention what you see should have actually happened in front of the camera but the film-maker can play fast and loose with what is filmed. Treat it as if the film-maker has cherry-picked what to show you in order to make a point or tell a story. After all, that is what has actually happened.

Dawkins shows are like this. In Root of all Evil he cherry picks footage to show religious people as raving lunatics. Of course that is the point of his documentaries: that behind the smiles and the good works of religious people lies personal convictions which are flawed and dangerous. Thus he has selected his footage to highlight that.

Such things can be useful for promoting discussion, and the odd bar fight, but cannot be expected to be convincing.

Tuesday, 12 October 2010

Beautiful Weekend

Had dear old Mum over for the weekend and the weather decided to be gorgeous for a change ... back to normal now.

We did the booze tasting at the Onetangi Rd Vinyard, which is well worth it. They basically give you half a glass of each bit of plonk they make, eight bits in all, for NZ$10.00 ... good value. That is four beers and four wines.

The blond makes a nice daytime or lunch beer, it is mellow and wheaty. Baroona Original is the standard beer, OK, a bit like Steinlager Pure. The Full Malty edition packs a wallop, and is good for a late afternoon sundowner. The dark ale is orangy, like it has orange peel in it ... I feel that all dark ales suffer from inevitable comparison with Guinness but this manages to be different enough to overcome the prejudice. Faves are the wheat and the malty.

Wines: 2 whites, a rose and a red
Cab Sav is a surprise with strong granny smith and cinnamon accents - wine for summer, have it with fruit. I forgot the other white because it was nothing special. The rose was the Sav with a bit of merlot for color - the result mellows out the apple tones making this more of a wine to have with meal - meat meal. The red was a Merlot and very smooth, slightly smoky.

Back at my place and the rest of the weekend was either sitting on the deck watching the birds (Tui's, fantails, riflemen and pigeons all payed a visit) or inside watching season 6 of 24. That was basically the weekend.

Spring is clearly here giving me a massive asthma attack after nothing all winter ... got another doctor visit to come then. Tomorrow I have marriage guidance courtesy the taxpayer and the Family Court. I'm quite nervous about this - if you visit the FC website and read the "advise to men" section it basically says "this is happening because you are a heartless bastard and you need to wake your ideas up" ... in contrast to the advice to women which is much more sympathetic. But we'll see. This one is solo, wife went first for diplomatic reasons, the next one will be together ... after that we are either getting back together (unlikely) or finalizing the property separation.

For now though - hello 24 season 7.

Thursday, 7 October 2010

Fair Go gets it wrong!

Oh dear.

At the end of the item "Spam Spat" on TVNZ's Fair Go program, the team provide some helpful advise to consumers who are plagued by spam email. They tell you to use the "unsubscribe" button required by law - or just to reply to the sender asking to be taken off the list.

This is fine as long as the email in question is legitimate advertising, however, spam is mostly unsolicited email of a range of types, including malicious email disguised as something else.

Malicious spammers love to be replied to. If you send them a "please unsubscribe me" letter, they will just subscribe you to every spam merchant they work for. It means that the email account is active you see, so there is someone reading the mail. It does not occur to them that you don't want to get it in the first place.

Really malicious spammers will include an "unsubscribe" button which actually installs malicious software like viruses or keyloggers or permanent cookies.


1. Never reply to spam
2. Never click on anything in spam

In general - never receive html or "rich text" emails. These allow images and buttons and so on to appear in an email - you don't need them to read your mail so don't enable them. Nobody ever got a virus off plain text. You'll still be able to read the email, it just won't be as pretty.

If the spammer follows NZ guidelines, then they will have a clearly identifiable company in there someplace. If you want to unsubscribe, and you have think the company is legitimate, then google for the company name online, browse to their company web page, and use their feedback form. It's not as easy as replying, but it is better than having a some criminal run up large debts against your name or finding out your computer has been used to spam millions of other internet users.

Tuesday, 5 October 2010

Welcome to GST

There seems to be a lot of concern over GST - compounded by the fact that hardly anyone gets the amount right. (I note that Fair Go was the only media to work out the math properly...) ... I've been waiting a bit for the dust to settle before commenting.

C'mon folks, we've been here before:

The thing about percentages is a percentage of something

The actual per cent part just means that you multiply by 100.

GST increases from 12.5 percent to 15.0 percent. That is an increase of 2.5 percentage points - please be careful here: it is not an increase of 2.5% of anything.

The increase in GST is actually 20% - because 2.5/12.5 = 0.2 ... that's the amount of the increase divided by the thing it is an increase of.

What we care about, though, is how much the prices will increase by. The old price is 112.5% of the untaxed price and the new price is (expected) 115.0% of the untaxed price. This is because the total price is 100% of the untaxed price plus tax. The percentage increase is the percentage point difference divided by what it is different from or 2.5/112.5 = 0.0222... which makes 2.22%

This means that something that used to cost about $50 (a bottle of whiskey for eg) will cost an extra $1.11 and a $2000 TV or computer will come out at $2044.44

What retailers actually do is a different story. Some will absorb some or all of the tax increase, effectively reducing their profits, while others will use this opportunity to put prices up even more and blame the government.

As far as the shop is concerned, 12.5/112.5 of what you pay them is tax, but if they don't want to increase how much they charge you, this will become 15.0/112.5 ... this means they used to give 11.11% of the asking price to the government and now they have to give 13.33% - an increase of 2.22 percentage points or 2.22/11.11 comes to 19.98%

To normal people it works like this. If you give a shopkeeper $900 for a product, $100 of that would have been GST. After the increase, the amount is $119.98 ... in effect that would leave the retailer with $780 for the sale instead of $800.

Got it? (You have to practise.)

Meantime, I see that the Commonwealth games is dominating TV for the next however long. If you enjoy sports, that is great. But I don't, so this sucks the big one. In particular, athletic sports are even more boring than team sports. At least soccer or rugby starts to make sense after a few beers.

Probably this experience is made worse by school athletic days - nothing like compulsory fun to destroy any appreciation a nerdy asthmatic kid may have had for pointless physical exertion.

I managed to get into town yesterday, picked up season 7 of 24, which should be good for a sleepless night, or, with discipline, two days CG coverage.