08 April 2009

On more in this vein

Following on from the previous post; I have been reading Ben Goldacre's excellent Bad Science (London; Fourth Estate, 2008, and see his blog here), and came across this quotation (I quote at greater length than Goldacre), which struck me as apposite;

In the South Seas there is a cargo cult of people. During the war [WW2] 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.

from Feynman R (1986) "Cargo Cult Science; Caltech Commencement Address, 1974" in Surely you're joking, Mr Feynman; adventures of a curious character London; Unwin Paperbacks p.340

The extract in blue refers precisely to the "going through the motions of scholarship" I castigated earlier, but the overall quotation goes further. Feynman argues against the process of simply assembling evidence in support of a case, and this accords with a point I make in discussing the characteristics of M level writing;
Most people ... amass a great deal of material to support their argument: but at Master's level this is not enough. You need to test the argument. So you also need to amass evidence against it, and to take account of counter-arguments and alternative positions, discussing either why they are not applicable in this case, or why you find them inadequate, inappropriate or morally reprehensible.
I'll return to this in a future post I'm beginning to think about discussing the usefulness or otherwise of theory. (But the above point is the only time I will ever aspire to refer to my views in the same breath as those of Richard Feynman!)

Incidentally, Feynman has latched onto only the most obvious features of the cargo cults, which are rather more sophisticated than he allows for. See inter al. Worsley P (1970) The Trumpet shall sound: a study of Cargo cults in Melanesia London; Paladin which takes a broadly Marxist perspective...

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