A history of randomization

Much of my current research involves randomized control trials (RCTs), in which participants or clusters of participants are randomized into a treatment group (or groups) and a control group. The treatment group gets some sort of intervention and the control group does not. If the sample size is large enough, randomization ensures that each group is ex ante identical and that therefore any difference in outcomes can be causally attributed to the intervention and not e.g. to selection bias or existing trends.

A couple of colleagues and I started talking about the historical origins of randomization in science. Most people associate this approach with clinical trials in medicine and epidemiology, which is indeed where they gained fame, but I was pretty sure that they had earlier and first been used in agriculture by the pioneering statistician and biologist Ronald Fisher. I was half right: Fisher did use them earlier, and his text on experimental design is a classic treatise laying out the principles of randomization, but he was not first.

Apparently the first reference to comparing treatment and control groups is in the Book of Daniel in the bible, where King Nebuchadnezzar orders his people to eat only meat and drink only wine (for their health). When some object, he allows them to eat only legumes and drink only water for 10 days, after which he compares their health to the “control” group of meat-eaters. They do better, so he allows them to continue their diet. Note, however, the lack of randomization and hence the possibility of a strong selection effect. The king appears to implicitly understand this, since he does not order everyone to switch to the new diet.

That story is told in this interesting medical history of clinical trials (as well as this follow-up article). It also discusses the famous streptomycin (for tuberculosis) trial of 1946 (published 1948), which is generally considered the first random trial in medicine. Indeed the wikipedia article on RCTs calls it the first published RCT, although as we shall see this is essentially incorrect. One of the medical histories bizarrely states, without citation, “The idea of randomization was introduced in 1923.” This is wrong by approximately three centuries.

A few years earlier, during the war, the british Medical Research Council performed a trial of patulin (related to penicillin) for the common cold. They didn’t explicitly randomize; instead they alternated patients to treatment vs control. That strikes me as a generally valid approach, and they also deserve a lot of credit for carefully double-blinding the study. Apparently there was also an early randomized experiment to test a potential immunization against whooping cough. But neither of these interventions proved efficacious, and the streptomycin trial was published first, so it takes the credit (within medicine).

Meanwhile the medical literature points back to Dr. James Lind, an 18th-century physician who decided to test various methods for treating scurvy while serving as a naval ship’s surgeon in 1747. He took 12 diseased sailors, split them into groups of two, and gave each of the six groups a different treatment (cider, sea water, nutmeg, etc). After 6 days one group showed marked improvement: those who had received oranges and lemons. Formally this wasn’t randomized, and the sample size was very small, but this is probably the first rigorous experiment along such lines.

However, the idea of randomization dates back to 17th-century belgian physician Van Helmont. As everyone knew at the time, bloodletting was a great cure for most ailments. Van Helmont agreed, but he thought that evacuation (i.e. inducing vomiting and defecation) was even better. To …

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Category: Psychology, Research, Science

Hard topics have easy answers

I’m a member of an ultrarunning email listserv, although I don’t post very often myself. Recently I got involved in a short back & forth which extended beyond running, and to which I devoted some thought, so it seems appropriate to ‘leverage’ that time and record it here. Plus one of the other members, a high school teacher, said he liked what I wrote so much he was going to read it to his class today!

The relevant bit starts when one contributor wrote:

Let me come to the defense of Chris’s point for a minute. As in high school, people sometimes sound as if they are saying “I may have only gotten a B on that test, but I didn’t really study at all.” There comes a point at which you think “there is no prize for getting the best grade with the least studying. Either you get a good grade or you don’t.”

This is a leisure activity for almost all of us. Nearly all of us could train more if we chose to. But we get whatever we get, and there is no added honor in saying, “but I hardly trained,” as if that makes your time more meritorious.

And I replied:

Well let me argue against Chris’s point (or at least a stylized version of it), just to play devil’s advocate.

I agree that boasting (or whining) “but I hardly trained” is not worth much at all. Answering the question “how well can I do at this race / distance / whatever with as much training as feasible?” is an interesting and worthy pursuit. But I would argue that it is also interesting and worthy (at least for some of us) to answer the question “how well can I do on (e.g.) 20-25 mi/wk?”  Not because it makes us cooler, or because we have more going on in our lives than anyone else, but because it’s simply a non-obvious question and I like challenges.

Training has to be efficient and highly optimized. Do you sacrifice long runs or speedwork or something else? Do you push hard every time? Do you run shorter 5-6 times per week, or longer (on average) 3-4 times per week? Do you strategize differently on race day, and if so exactly how?

When someone asks how to do better, the easy answer is “train more” – because that is almost certainly the correct answer. But if for whatever reason that isn’t going to happen, what is the answer? This requires more thought, and I like thinking about it. I may not run faster, but I enjoy the thinking as well as the running, and it is hard work in its own way.

Responding to my claim that training more is the easy answer, someone else wrote:

That’s the easy answer? Quick, if only there were a way you could sell it!

I knew he wasn’t being serious, but I was still thinking about the topic and decided it was worth a slightly more complete exposition:

I know you’re being facetious, but you’re exactly right. As with dieting (also discussed here ad infinitum) and careers and most things in life, the basic answer is fairly obvious and it is easy to come up with (not to do). Train More. For weight: Eat Less (and more veggies). For work: Learn to Fish (i.e. take the effort to learn the underlying method not just the outcome; try to get it right the first time). For relationships: Be Generous.

None of these are easy to do, and none of them are easy/possible to sell because they’re

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Category: Philosophy, Psychology, Running

My affiliates (take 5)

Continuing from last time, my latest business cards:

  • Founder, Employee Loan Solutions
  • CEO, Sunrise Banks
  • President – Financial Services, H&R Block
  • Revenue Manager, Hilton Curaçao
  • Senior Policy Advisor, Office of Consumer Policy, US Dept of the Treasury
  • Monitor, California Attorney General’s Office
  • Vice President – Customer Lifecycle Management, American Express
  • Lead Health and Education Specialist, Human Development Network, The World Bank
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Category: Miscellaneous

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Julian C. Jamison

I'm an economist, researcher, traveler, runner, and astronaut-in-waiting. I enjoy pondering human behavior, including both what we do and what we ought to do - either to maximize our well-being or in pursuit of some other goal.


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