Showing posts with label feynman. Show all posts
Showing posts with label feynman. Show all posts

Friday, February 23, 2007

The problem with testimonials

A common technique used to sell an idea to present accounts of how its use has been successful. It's an old technique for promoting products, political candidates and even religious beliefs. But too often it even sneaks into supposedly objective science, as one of my heroes, Richard Feynman, observed in 1974. Here's an excerpt from the address where he describes the strange phenomenon known as "cargo cults" that has occurred in isolated South Sea island communities. It's really about honesty, which can be compromised when we are partisans for a particular point of view. Be suspicious of any system that does not publish its mistakes and failures along with its successes.
Cargo Cult Science

In the South Seas there is a cargo cult of people. During the war they saw airplanes with lots of good materials, and they want the same thing to happen now. So they've arranged to make things like runways, to put fires along the sides of the runways, to make a wooden hut for a man to sit in, with two wooden pieces on his head to headphones and bars of bamboo sticking out like antennas -- he's the controller -- and they wait for the airplanes to land. They're doing everything right. The form is perfect. It looks exactly the way it looked before. But it doesn't work. No airplanes land. So I call these things cargo cult science, because they follow all the apparent precepts and forms of scientific investigation, but they're missing something essential, because the planes don't land.

Now it behooves me, of course, to tell you what they're missing. But it would be just about as difficult to explain to the South Sea islanders how they have to arrange things so that they get some wealth in their system. It is not something simple like telling them how to improve the shapes of the earphones. But there is one feature I notice that is generally missing in cargo cult science. That is the idea that we all hope you have learned in studying science in school -- we never say explicitly what this is, but just hope that you catch on by all the examples of scientific investigation. It is interesting, therefore, to bring it out now and speak of it explicitly. It's a kind of scientific integrity, a principle of scientific thought that corresponds to a kind of utter honesty -- a kind of leaning over backwards. For example, if you're doing an experiment, you should report everything that you think might make it invalid -- not only what you think is right about it: other causes that could possibly explain your results; and things you thought of that you've eliminated by some other experiment, and how they worked -- to make sure the other fellow can tell they have been eliminated.

Details that could throw doubt on your interpretation must be given, if you know them. You must do the best you can -- if you know anything at all wrong, or possibly wrong -- to explain it. If you make a theory, for example, and advertise it, or put it out, then you must also put down all the facts that disagree with it, as well as those that agree with it. There is also a more subtle problem. When you have put a lot of ideas together to make an elaborate theory, you want to make sure, when explaining what it fits, that those things it fits are not just the things that gave you the idea for the theory; but that the finished theory makes something else come out right, in addition.

In summary, the idea is to give all of the information to help others to judge the value of your contribution; not just the information that leads to judgement in one particular direction or another.

Monday, December 11, 2006

I doubt, therefore I think

** Feynman on "The Role of Scientific Culture in Modern Society." Conclusion of a talk given at the Galileo Symposium in Italy in 1964. From “The Pleasure of Finding Things Out."
What then is the meaning of the whole world? We do not know what the meaning of existence is. We say, as the result of studying all of the views that we have had before, we find that we do not know the meaning of existence; but in saying that we do not know the meaning of existence, we have probably found the open channel – if we will allow only that, as we progress, we leave open opportunities for alternatives, that we do not become enthusiastic for the fact, the knowledge, the absolute truth, but remain always uncertain – [that we] “hazard it.” The English, who have developed their government in this direction, call it “muddling through,” and although a rather silly, stupid sounding thing, it is the most scientific way of progressing. To decide upon the answer is not scientific. In order to make progress, one must leave the door to the unknown ajar – ajar only. We are only at the beginning of the development of the human race; of the development of the human mind, of intelligent life – we have years and years in the future. It is our responsibility not to give the answer today as to what it is all about, to drive everybody in that direction and to say: “This is a solution to it all.” Because we will be chained then to the limits of our present imagination. We will only be able to do those things that we think today are the things to do. Whereas, if we leave always some room for doubt, some room for discussion, and proceed in a way analogous to the sciences, then this difficulty will not arise. I believe, therefore, that although it is not the case today, that there may some day come a time, I should hope, when it will be fully appreciated that the power of government should be limited; that the government ought not to be empowered to decide the validity of scientific theories, that this is a ridiculous thing for them to try to do; that they are not to decide the various descriptions of history or of economic theory or philosophy. Only in this way can the real possibilities of the future human race be ultimately developed.