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Prior Probability

June 26, 2009 Leave a comment

A common comment I hear in skepticism discussions is that extraordinary claims require extraordinary evidence. This means that if someone is making a claim contrary to what is considered to be well established science then they need to produce more proof than they would for a less controversial claim.

I have always been a bit unsure about this idea. Why should new ideas require more proof than well established ones? Doesn’t that make science biased against new ideas? After listening to another Skeptics’ Guide to the Universe podcast I think I now have a new perspective on the idea and it isn’t really a source of bias after all.

It gets back to the idea of prior probability. The thing is that you have to consider the total evidence for an idea. If a new idea fits in with all the existing evidence then it already has a head start. If it contradicts what we already know then it has to overcome all of that negative evidence before it even enters the realm of positive support.

As an example consider homeopathy. That is the belief that samples of substances which cause a disease when diluted to unbelievably low concentrations can actually treat the same disease. There are a few problems though. First, the dilutions are so great that there is none of the original substance left at all, its just water (or some sort of filler in solid homeopathic remedies). Second, why should something which makes the condition worse in normal concentrations make it better when its diluted?

There have been studies which seem to support homeopathy but most (maybe all) have been found to be deficient in various ways. One of the most famous was shown to be caused by a researcher at the lab deliberately changing the results to suit the outcome they wanted.

If there were a similar number of results supporting a theory which fitted in with what we already know then we could take it more seriously, but having conflicting results, the positive results coming from poorly designed experiments, and having no prior probability means that homeopathy is just not believable.

One alternative explanation for the observed phenomena is the placebo effect. There is plenty of evidence this really happens and it fits with what we already know so that seems like a much better explanation of unusual claims like homeopathy than the alternative explanation of water remembering the “vibrations” of previously dissolved substances.

Prior probability is weak for many forms of pseudoscience, superstition, and the paranormal, for example psychic abilities, UFOs, healing prayer, near death experiences, creationism, astrology, acupuncture, Nostradamus, numerology, reincarnation, flat Earth, the Loch Ness monster and bigfoot.

Some of those are more likely (or less unlikely) than others and I’m sure there are many I’ve missed out but as more scientific evidence accumulates which contradicts those ideas they become less and less likely and the evidence to prove them becomes greater. So I think the idea that “extraordinary claims require extraordinary evidence” makes sense after all.

Most Important Software

June 25, 2009 Leave a comment

I recently read an article about what the author thought were the 10 most important (they used the term “industry-changing”) programs in the history of computing. Since I have been working with computers for almost 30 years now I thought I was probably in a position where I could reasonably evaluate the claims in the article and offer my own perspective, so here goes.

Number 10 was the Oracle database. I guess Oracle is important but I don’t know whether it really deserves to be ranked above others such as Access (remember I’m not making judgements in quality here – just influence) or MySQL. Maybe it depends on which sector you work in. Oracle is important in the corporate world and I haven’t had much to do with that area so I could easily have missed this databases’s importance.

Number 9 was PGP. I think the idea of public key encryption is important (especially to safe transactions on the internet) but I don’t know if I would rate PGP itself that highly.

Next, at number 8 was Apache. I certainly agree with this one. I do a lot of web development and all my systems are running Apache. It also has by far the greatest share of the web server market (easily beating Microsoft and it gets extra merit for that alone). The web is probably the most important internet service to most people today and will become more important as web apps are more widely used so yes, Apache should be up there.

Microsoft had to be in there somewhere and in place number 7 is Microsoft Office. As much as I despise it I cannot deny how important it is because it is the standard for some of the most common tasks computers are used for: word processing, spreadsheets and presentation. I would be happier if Office wasn’t so dominant but the fact is that it is so it deserves a place on this list.

At position 6 was something called Dr. Solomon’s Antivirus Toolkit. I had to think about whether I had really even heard of this before but because I mainly work in the Mac world anti-virus software has never been a major priority for me. But I guess for those people who choose to use the inferior platform which does suffer from endless viruses this sort of program is important.

At number 5 was Adobe Photoshop. I totally agree, Photoshop is a brilliant program as well as an important one. If I could only have a small number of programs (say 5) on my computer Photoshop would be amongst them (along with a web browser, a good text editor, a good game, and a program to open common document formats like PDF, doc, etc). And as a serious amateur photographer Photoshop is now an essential part of my photographic creative process. It made computers serious graphical and photography tools and really belongs on this list.

Number 4 was something called SNDMSG which was an early email type program. There is no doubt that email is extremely important and if this program (which I really know very little about) was what caused email to originally develop then I will take their word for it.

Number 3 was Lotus 1-2-3, an early spreadsheet. But I would have thought that it was just a copy of Visicalc anyway so why not say that Visicalc was the important program in this category? I still remember using Visicalc for the first time (on an Apple II) it was just magic how hundreds of numbers would recalculate instantly even on those primitive machines. It really was the revolution which made personal computers a serious tool instead of a toy.

Coming in at number 2 was Quark Xpress. I found this a bit puzzling because I would have thought that PageMaker really deserved the place for the original influential DTP program. I was a great fan of XPress version 3 but now that I do almost everything on-line I have little use for it. It is a very nice program though, but has recently become a bit irrelevant since the introduction of In Design.

At number 1 (and I assume that means it was most influential) was Mosaic, the “original” full featured (by the standards of the time) web browser. I was around when the internet was born and I used Mosaic. Since then web browsers have just become more and more important and if cloud computing takes off as many people predict then the browser will just be even more essential. So I guess in many ways Mosaic does earn the top spot.

So that’s it. A fair list I think, although I would disagree with a few of those selections. Also, what about an entry for most influential game and most influential programming tool? Those are two aspects of computing which are also very important and deserve a mention.

Binding Referenda

June 24, 2009 Leave a comment

We live in a democracy which means that the people are supposed to have the real power, but how far should that concept be taken? This is the question effectively being asked with the debate on citizen initiated referenda which is happening in New Zealand at the moment.

A CIR must be run if a petition gains a certain number of votes (I can’t remember how many it is but its a fairly respectable number). Everyone on the electoral roll in New Zealand gets to vote on the issue so it costs quite a lot to run, but the final outcome isn’t binding on the government. Even if everyone voted in favour of something the government is under no obligation to carry out that wish. The question is then: should they be?

Personally I don’t think so although the poll run on the Herald web site today suggests I’m in the minority because 75% of the participants there voted that referendum results should be binding.

The problem with referenda is that they are generally meaningless. In the ones which I recall the questions have been so poorly worded that the outcome really means nothing. The current referendum poses this question: “Should a smack as part of good parental correction be a criminal offence in New Zealand?” Its a silly question designed to elicit a particular response and I remember previous questions about crime and punishment being equally worthless.

As I blogged about on 2009-06-18 in an entry titled “Ask a Silly Question” I don’t intend to vote one way or the other. Instead I will record a complaint about the process itself and send the paper back.

So do people really think that votes on questions posed in such emotive, biased and illogical terms should be binding? I certainly hope that if people really stopped to think about it they would realise that this is not a process we should be following. I’m afraid the greatest extent that the people should gain true power is through who they vote for at each general election, and I’m not even sure they are responsible enough to even do that!

What is Happiness?

June 23, 2009 Leave a comment

What is happiness? According to a podcast from the Philosophers’ Zone its many things and that is the cause of many of the disagreements and confusion about the subject. The podcast split the concept into 6 different areas but I think it can be simplified into two: a short term but more true type which could be associated with pleasure or enjoyment, and a longer term but more abstract idea associated with contentment or satisfaction.

So why am I talking about such an abstract and possibly pointless topic here? Well it gets back to how many studies which have been done on the subject of happiness seem to produce partly consistent and partly conflicting results, and I wanted to explain why!

Specifically I want to mention studies which examine the link between financial success and happiness, in other words: does having more money make you happier? Well the answer is yes… and no. Like many questions in the area of human psychology it is complex.

The consensus seems to be that up to an income of about US$40,000 people do get happier. Especially up to $27,000 people become rapidly happier as their income increases. After $40,000 the result depends on the exact methodology used until you reach $125 million and after that people start getting rapidly happier again!

In the area between $40 thousand and $125 million the result shows either no real difference at all or a slight but real increase as income increases. When happiness is measured using techniques which look at what psychologists call positive/negative affect there is no difference but when life satisfaction is measured the result is a slight increase.

The first technique measures the real mood of people as they would report it at an instant of time and the second is a more introspective report of their satisfaction with life in general.

The first seems more genuine so from that we could say that, after a certain level is met, people don’t get happier as they get more money (until you reach that figure of $125 million but that is probably the result of measuring the response of people with unusual personalities)

The second seems to be measuring how happy people think they should be rather than how happy they really are. So maybe people think that they get happier as they get richer but in fact don’t. The point is that happiness is not a well defined concept so when analysing results of experiments or studies measuring it you should be cautious.

So if we lived in a society which wanted to maximise happiness (at least the component of happiness associated with money) we could redistribute the wealth so that everyone gets at least US$40,000. Of course that would never happen but its an interesting idea.

A Classic Experiment

June 22, 2009 Leave a comment

Many years ago when I was a student I majored in computer science (of course) and psychology. Computing was a new and exciting field at the time (maybe even more than it is now) so that was an interesting subject but psychology was also fascinating: especially paranormal psychology and social psychology.

The lecturer for paranormal psych was excellent. He had studied some of the more well known psychics and other people who claimed to have special abilities (for example Uri Geller who was very popular at the time) and I think that might have been a major factor which lead me to skepticism and atheism.

I also found some of the social psych experiments interesting. My favourite (and a favourite for many people who have studied psychology) was the Milgram experiment, a classic published in an article titled “Behavioral Study of Obedience” published in the Journal of Abnormal and Social Psychology in 1963 by Stanley Milgram, a psychologist at Yale University.

The reason I mention this rather obscure piece of social science history is that I listened to a podcast about it today. One of the interesting points was that the experiment could not be repeated today because it wouldn’t get past an ethics committee. Even at the time it was controversial and Milgram left Yale because of this.

But I haven’t described the experiment yet, so here it is…

People were recruited to sit in a room equipped with some electrical controls. They were instructed to ask the subjects of the experiment in another room questions and give them a shock if they got it wrong. The idea was to see if they could improve their learning through punishment. Each wrong answer was punished with a bigger shock until many begged for the shocks to stop. But the people running the experiment told the subjects to continue giving the shocks and most did.

But that wasn’t the real experiment of course because the people being shocked (who weren’t being shocked at all and were just acting) were really working with the experimenters. The real subjects were the people giving the (fake) shocks and the real purpose of the experiment was to see if people would do what they were told to do even when they knew it was wrong.

Only about a third of the subjects refused to give out all of the shocks, even up to the “lethal” level where the person being shocked had (fake) convulsions or blacked out. The rest continued to the end of the experiment.

This seemed to show that people would respond to authority figures by acting in a way they never would otherwise. This was used to explain the immoral behaviour of people in tyrannical regimes like Nazi Germany. Of course, its overly simplistic to say that this is the reason everyone behaves badly but it no doubt explains some of the behaviour of some people.

There was undoubtedly some trauma involved for the subjects (I mean the real subjects here, the ones pressing the buttons, not the ones getting the fake shocks) and that’s why it could never happen today but is that fair?

Some of the subjects reported gaining an insight into their own behaviour which helped them avoid similar situations in real life. That sounds like a good thing. And the experiment did reveal interesting aspects of human behaviour and that is valuable too.

I suspect there are many more traumatic events in most people’s lives which are more negative and which don’t create some good in balance, so why can’t experiments like this still happen? As long as the subjects were told they might be deceived and might experience some mild stress or anxiety I don’t think there’s a problem.

Social psychology experiments today don’t seem to be as interesting although experimenters are now forced into using even more subtle techniques which are intriguing in themselves. Still, ethics committees are a definite barrier to cool experiments!

Yet Another New Toy

June 19, 2009 Leave a comment

Every now and again I post an entry here talking about a new toy I have bought. For many years now (like about 30) I have been a serious amateur photographer. Technology moves on and its worth updating camera equipment every 2 or 3 years so now was the time to do it again.

In fact the time to do it was near the end of last year but my previous attempt at updating my camera went terribly wrong! As I have commented on in the past I am a great fan of on-line auction sites, mainly TradeMe, New Zealand’s main (almost only) site.

Last year I bought a new camera and lens on TradeMe and paid up my NZ$2300 (good cameras aren’t cheap) and patiently waited for the camera to arrive. After a few days it became obvious something was wrong and it turned out the whole thing was a scam run by a trader who is currently being prosecuted by police.

I have always used Canon cameras but that camera was a Nikon (a D90) which I chose because it had features Canon didn’t have at the time. Since then Canon has introduced an even better (and cheaper) camera than the Nikon which I have also bought on TradeMe. As long as it turns up in the next few days I will be happy. Every day delay will be a cause of concern!

But really on-line auctions are fairly safe. I have bought thousands of dollars worth of gadgets on-line and only been ripped off once. It was unfortunate that the rip-off involved one of the most expensive items I bought though!

So what progress has digital photography made since my last camera? Well quite a lot actually. My previous camera was a Canon EOS 350D, an 8 megapixel digital SLR, and its still a very fine camera, even 3 years after I bought it. Its fast and reliable and can produce brilliant quality images.

The new camera (an EOS 500D) has a few advantages though. First, it has almost twice as many pixels (but I have never seen more pixels as necessarily critical). More importantly it has a high definition movie mode, live preview, better low light performance, a much bigger and better display, an image stabilised lens, and a few other enhancements.

Ironically this has given the dSLR feature parity with many compact cameras which have had most of those features (in some form) all along! But compact cameras really just can’t compete for real photography. I had to use two of them (a Canon and a Kodak) recently and the speed, responsiveness, flexibility and quality was rubbish compared with even my old dSLR. In ideal conditions (plenty of light, slow moving objects, etc) they are OK but push the limits even slightly and they often don’t work well at all.

A great example of the superiority of the SLR was an air show I took photos at a few years back. The previous show I had used a fairly advanced (at the time) compact camera (a Canon G6) and the photos were OK but lack of magnification (with just a 4x zoom), inferior performance at higher sensitivity settings, and slow general responsiveness meant none of my photos were that great.

When I used the SLR instead things were so much better. The speed meant all the aircraft were right in the middle of the frame instead of escaping out the front! And the long telephoto (equivalent 450mm) meant I could zoom right into the action, including shots of the pilots actually sitting in the aircraft.

So when the 500D turns up (it will this time because I have used a reliable trader) I expect that my photos will be even better, especially in low light, but also I should be able to create some nice high definition movies. They should look great on my plasma TV!

I do have a lot of expensive toys but at least I use them a lot. The previous camera had done 15,000 photos (Canon say the shutter is good for over 100,000) so it go a lot of work. I also upgraded my telephoto zoom lens which I had been using for 25 years. It still worked fine but I got the opportunity to do a minor upgrade for almost nothing so I took it.

I’ve owned a lot of Canon (film and digital) cameras over the years: An AL-1, an A-1, two T-90s (that’s another story), and EOS-5, an EOS 350D and now the EOS 500D. They have all been brilliantly reliable and easy to use. If the 500D is up to this standard I will be happy enough! I’ll do a review once I’ve used it for a few weeks.

Ask a Silly Question

June 18, 2009 Leave a comment

A major controversy erupted here in New Zealand over a year ago now over a new law which removed the legal defence of “reasonable force” for physically assaulting kids. Inevitably it became known as the anti-smacking law when it came into force.

Naturally the conservative part of the population hates it, including a lot of the more conservative Christian groups (I always thought that Christianity was about peace and forgiveness but apparently that’s not true). It was only a matter of time before these groups (who seem to enjoy inflicting their warped views on everyone else even though most of them are too old to have smackable kids anyway) tried some sort of stunt to have the law reversed and now it looks like they might be starting.

A citizen initiated referendum has been contrived with the question: “Should a smack as part of good parental correction be a criminal offence in New Zealand?” Many people are pointing out that this is a deliberately misleading way to word the question but we have a history of that sort of nonsense here so it should be no surprise.

Since the law was introduced there have been no good parents made into criminals because of it. In fact there have been few bad parents affected as well.

I do think that smacking might be an effective method of controlling some extremely difficult kids but I think they would be in the minority. By the same logic there are many adults who might benefit from a “good thrashing” so maybe that should be legal too. The thing is that the benefit gained by allowing physical violence is outweighed by the disadvantages so the argument that smacking is an effective way of control available to parents doesn’t really make sense.

And what about the argument that “it never did me any harm”. Well the people who make this point should maybe look at themselves a bit more closely. Many of them are recommending violence against children without knowing the real situation and many are old enough that they don’t have kids themselves. It seems a rather unhealthy attitude to me. Maybe one that arose as a result of a violent childhood?

The prime minister and leader of the opposition have both said they won’t vote on this issue. A conservative MP has said he will but it looks like he’s likely to vote the opposite way to what he likely intends. Maybe the question is not only dishonest but also confusing.

So what should we do when the ballot arrives? Answering the question either way is just encouraging more political grandstanding through the same mechanism in the future. Not sending the paper back indicates apathy. I intend to spoil the ballot, make a comment on it regarding wasting taxpayers’ money, and send it back. If a lot of people do this maybe it will get through to the dishonest group behind this referendum that we have seen through their dirty little trick.