I am only six months behind in answering thoughtful emails from readers. Here is one from Stephen Puryear:

Dr. Briggs, please go back and elaborate on your ideas about why randomizing is such a bad idea. So far I’m intrigued but I don’t really understand your position. The fact that its the “gold standard” that everyone bows down to with no further thought makes me even more curious to hear your complete thoughts and analysis.

It should be clear at this late date that that which everybody bows to is no longer a blanket recommendation in a thing’s favor. We have science pozzing, we have the replication crisis, and we have the slo-mo collision of physics with metaphysics. All old ideas are fair game.

Randomization was never a good idea for science, but it sometimes can be a good idea for scientists.

I give the example in Uncertainty of the Apostles casting lots to decide on a replacement. Sounds like randomization, or worse.

Were the apostles hoping God would use (cause) the most minimal physical force necessary to shift the lots in His preferred direction in order to guide the apostles to the best choice? Or were the apostles equally split among choices and, wanting to avoid strife and acrimony, removed the choice (cause) to something which they could not predict or influence (cause)?

Cause is emphasized because, of course, the event of choosing a new apostle had a cause, or causes. There will be all kinds of causes associated with the casting of the lots (as there are with dice etc.), all of which are there even when we don’t know or can’t control them. It’s possible God directly intervened in a miraculous way in those causes to affect the outcome. But it’s also possible the ordinary secondary causes operated in their usual way to cause the outcome.

The apostles could have voted, or had several rounds of voting, but with voting there are winners and losers, with both sides unhappy with the result. The losers wanted to win, and the winners realize they could have lost. Look what voting does to a democracy.

How much better to say “Let the cause be other than us!”

The key to this randomization was that the causes could not be manipulated, or could not be (largely) known. Whatever causes affected the outcomes, these would not be the apostles themselves, except for the trivial causes of collecting the lots and so forth. If there was instead an election, the causes would have been naked and obvious.

This kind of randomization can and should be used whenever there is suspicion that the causes of the effect can be manipulated in undesired and undesirable ways. The stock example is the referee doing the coin flip.

Referees doing coin flips would be an awful way to learn the causes of coin flips, though. Yes, we could set up a grand “randomized controlled experiment”, but why not instead very carefully control the known or suspected physical causes? Just as physicists actually do in their real experiments?

What are called “controlled” trials usually aren’t. They’re found in medicine and agriculture, and things like that, for the simple and obvious reason that the causes of effects are largely unknown. The causes of an electron taking a certain path are far fewer and simpler than what stopped a man from developing liver cancer, but still somewhat unknown or the experiments would never be run for the electron. Main causes might be known, but myriad small ones aren’t. The controls, when they exist, are for aspects that are probably or known partial causes like sex in medicine (well, in the old days before transanity hit), and plot placement in agriculture.

The only reason randomization should be used in any trial is because we cannot trust the interested experimenter. The classic example is of a doctor interested in a new treatment. He may, scrupulously or not, send the sicker patients to the old treatment. Forcing him to randomize—i.e. removing control of patient placement to some unpredictable cause—removes the causes made from his interest. Of course, if he is the attending physician (or biologist etc.) he may still treat the patients differently, hence the need for blinding.

Blinding is exactly the same as randomization. They both remove the ability to manipulate known or suspected causes of an effect. Or try too. Men are natural con artists.

Now, as for whether randomization does anything mystical to the experiment, as frequentists attest, we can dismiss as superstitious nonsense. There is no guarantee, and even the positive definite chance, that randomization can screw up control of a known or suspected cause. It could happen, for example, in small trials, that all the men end up in one group, and women the other. So we “control” for sex, by forcing a split.

Well, since we don’t know all the causes of the effect, hence the experiment, randomization could just as easily stack the deck for any or all of these uncontrolled causes. And we’d never know it! If we knew it, we would have controlled for them, like we did with sex. Randomization, therefore, does nothing. It is control that is wanted.

I stand by my recommendation that the best way to design experiments is, blind when you can, and have a disinterested panel control the placement of each patient (or crop of whatever). Certainly do not be tied to the old, proven wrong, methods of statistics. Understanding cause is the reason for the experiment: acknowledge that.

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