Archive for August, 2007

Probability of Occurring by Chance

Tuesday, August 14th, 2007

In this post at squareCircleZ, Professor Bruce Armstrong from the Sydney Cancer Centre at the University of Sydney is quoted as saying “The probability the that increase is due simply to chance is about one in a million so we are looking at something that is almost certainly a real increase in risk”. But this is almost certainly a misstatement since the probability that something is due simply to chance is not computable and probably not even meaningful whereas the probability of its happening in a randomly chosen situation from a well defined population of cases is meaningful and often computable. Either concept could be expressed by the ambiguous title of this post but they are definitely NOT the same – as can be seen from the following example. If I win the lottery without cheating then the probability of it having happened by chance (in the sense of having only chance factors involved) is in fact 1 but the probability of it happening by chance (ie of it happening given that only chance factors were involved) was less than one in a million. Of course, if we don’t assume that I didn’t cheat, the probability that my win was due only to chance may be less, but in any event it is not the same as my chances of winning a fair game. For a more practically relevant example consider the case of an experiment which identifies an effect of some sort “at the 95% confidence level”. What this means is that the probability of the observation occurring if only random effects were present is no more than about 1 in 20. But then in a set of many trials it is likely that up to about 5% of them will actually appear to show the effect. Users of statistics need to be aware of this distinction since in an experiment which collects more than six variables (as many in the social sciences do) there are more than 21 pairs to consider and so in an average such experiment at least one such pair will seem to have a significant relationship even when no such relationship actually exists.

All this is actually relevant to the story about cancer clusters since, in a world with several million observed groups of a hundred or so people, if the chance of a cluster happening given only random factors is one in a million then we may expect to see several such clusters occurring just by chance.

Leaning Tower Illusion

Sunday, August 12th, 2007

My friend Gerry Pareja forwarded a link to this story from ‘Improbable Research’ about the first prize winner in the Neural Correlate Society’s 2007 Illusion of the Year contest.

The image certainly is pretty cool. But to test the explanation I tried covering each image in turn and the effect was still there! I wondered if there was a perceptual delay effect in that our memory of one picture affects our interpretation of the other but then I also noticed that the effect changes depending on where the picture is in our field of view. If I position myself facing the right hand edge of the monitor, then the right hand tower seems more vertical and the left one almost seems to lean left or backwards. So the illusion may be more (or at least partly) due to the fact that in the absense of other visual cues in the picture we tend to interpret as if viewed from the direction at which we are looking at the picture – ie we interpret the picture edge as a window frame.

Basskin Misrepresents Media Levy

Friday, August 10th, 2007

David Basskin, Director of the CanadianPrivate Copying Collective, has written a letter to the Star in response to Michael Geist’s earlier comments about the media levy and its prospects of its being extended to mp3 players and perhaps even computer hard drives.

Basskin says “The private copying levy is an important source of revenue for music-rights holders and is an issue of fairness”, and goes on to claim that “The levy is often misunderstood. It is not a tax or subsidy, but payment to individual rights holders for use of music by Canadians in the privacy of their homes. Compensation for use – that’s fair”.

But of course the levy is NOT fair because it extracts funds from people who purchase data storage media for purposes having nothing to do with the products of Basskins’ clients and so in fact it IS a tax and subsidy.

What is particularly frustrating about this is the fact that there is a perfect opportunity for the sellers of music recordings to obtain compensation for whatever pattern of reproduction they expect from their customers, and that is at the point of sale. Extracting that compensation later from others who may have no interest in the product just amounts to artificially lowering the price. This may be good for sales and it may even be in the public interest to subsidize artistic products in some way, but this particular approach to gaining that subsidy is fundamentally dishonest and the legislators who were persuaded to go along with it have been conned and bamboozled.

One other aspect of this situation that is worth mentioning is that many who object to the levy might still be willing to entertain a more honestly defined subsidy – paid from honestly defined taxes. But taxes should be collected by the government not by private organizations.

Bad Law

Friday, August 3rd, 2007

The peace and wellbeing of society is harmed by laws whose perceived unfairness or unenforceability reduces public respect for the law.

In a large body of legislation it is hard to avoid parts which will appear unfair to some, but it is foolish to unnecessarily enact provisions whose manifest unfairness will be frequently imposed on large segments of the population.

A case in point is the media levy in Canadian copyright law. (more…)

Media Company Thieves Coming Back For More

Thursday, August 2nd, 2007

In TheStar.com – entertainment – Tax on MP3 players may return, David Basskin, director of the Canadian Private Copying Collective, is quoted as saying:

“When you have bought a CD, you don’t own the music – you own the copy of the music that you’ve purchased,” he says. “You’re not buying the rights to make copies.”

“People are going to do private copying, and the levy legitimizes it and provides compensation to the people who created the music. It’s pretty hard to say why that’s not fair,”

No its bloody well not hard to see at all!!!

{Warning:obscenities coming} (more…)

Big Guns Join Fight Against Illegal Copyright Notices

Wednesday, August 1st, 2007

Michael Geist brings some good news in – Complaint Filed With FTC Over Copyright Notices. But it is a bit sad that it is only with the support of big businesses that there is any hope of defending public access rights. If there were no major segment of the economy interested in protecting these rights would they just disappear?

AlterNet: Environment: Exposed: The Truth Behind Popular Carbon Offsetting Schemes

Wednesday, August 1st, 2007

AlterNet: Environment: Exposed: The Truth Behind Popular Carbon Offsetting Schemes