Quotes

Galen and clinical trials

Posted on by John

Here’s a quote from the Greek physician Galen (c. 130-210 A.D.)

All who drink of this remedy recover in a short time, except those whom it does not help, who all die. Therefore, it is obvious that it fails only in incurable cases.

Imagine a dialog between Galen and a modern statistician.

Stat: You say your new treatment is better than the previous one?

Galen: Yes.

Stat: But more people died on the new treatment.

Galen: Those patients don’t count because they were incurable. They would have died anyway.

The problem with Galen’s line of reasoning is that it is not falsifiable: no experiment could disprove it. He could call any treatment superior by claiming that evidence against it doesn’t count. Still, Galen might have been right.

Now suppose our statistician has a long talk with Galen and tells him about modern statistical technique.

Galen: Can’t you look back at my notes and see whether there was something different about the patients who didn’t respond to the new treatment? There’s got to be some explanation. Maybe my new treatment isn’t better for everyone, but there must be a group for whom it’s better.

Stat: Well, that’s tricky business. Advocates call that “subset analysis.” Critics call it “data dredging.” The problem is that the more clever you are with generating after-the-fact explanations, the more likely you’ll come up with one that seems true but isn’t.

Galen: I’ll have to think about that one. What do you propose we do?

Stat: We’ll have to do a randomized experiment. When each patient arrives, we’ll flip a coin to decide whether to give them the old or the new treatment. That way we expect about the same number of incurable patients to receive each treatment.

Galen: But the new treatment is better. Why should I give half my patients the worse treatment?

Stat: We don’t really know that the new treatment is better. Maybe it’s not. A randomized experiment will give us more confidence one way or another.

Galen: But couldn’t we be unlucky and assign more incurable patients to the better treatment?

Stat: Yes, that’s possible. But it’s not likely we will assign too many more incurable patients to either treatment. That’s just a chance we’ll have to take.

The issues in these imaginary dialogs come up all the time. There are people who believe their treatment is superior despite evidence to the contrary. But sometimes they’re right. New treatments are often tested on patients with poor prognosis, so the complaints of receiving more incurable patients are justified. And yet until there’s some evidence that a new treatment may be at least as good as standard, it’s unethical to give that treatment to patients with better prognosis. Sometimes post-hoc analysis finds a smoking gun, and sometimes it’s data dredging. Sometimes randomized trials fail to balance on important patient characteristics. There are no simple answers. Context is critical, and dilemmas remain despite our best efforts. That’s what makes biostatistics interesting.

Related: Adaptive clinical trial design

 

Three quotes on simplicity

Posted on by John

It’s easy to decide what you’re going to do.  The hard thing is deciding what you’re not going to do.
Michael Dell

Clutter kills WOW.
Tom Peters

Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius — and a lot of courage — to move in the opposite direction.
Albert Einstein

Being busy

Posted on by John

From A Bias for Action:

The simple fact is that being busy is easier than not.  Most managers cannot admit that a fragmented day is actually the laziest day, the day that requires the least mental discipline and the most nervous energy.  Responding to each new request, chasing an answer to the latest question, and complaining about overwhelming demands are easier than setting priorities.

In praise of tedious proofs

Posted on by John

The book Out of Their Minds quotes Leslie Lamport on proofs:

The proofs have been carried out to an excruciating level of detail … The reader may feel that we have given long, tedious proofs of obvious assertions. However, what he has not seen are the many equally obvious assertions that we discovered to be wrong only by trying to write similarly long, tedious proofs.                   

See Lamport’s paper How to Write a Proof. See also Complementary validation.

Six quotes on digging deep

Posted on by John

Here are six quotes I’ve been thinking about related to digging deep into whatever is in front of you, making uninteresting work interesting.

Richard Feynman:

… nearly everything is really interesting if you go into it deeply enough …

G. K. Chesterton:

There is no such thing on earth as an uninteresting subject; the only thing that can exist is an uninterested person.

William Blake:

To see a world in a grain of sand,
And a heaven in a wild flower,
Hold infinity in the palm of your hand,
And eternity in an hour.

King Solomon:

Whatever your hand finds to do, do it with all your might …

James Woolsey:

If you’re enthusiastic about the things you’re working on, people will come ask you to do interesting things.

King Solomon:

Wisdom is in the presence of the one who has understanding, but the eyes of a fool are on the ends of the earth.

Update: See the related post God is in the details.

Faith and reason

Posted on by John

From Saint Augustine:

Heaven forbid that God should hate in us that by which he made us superior to the animals! Heaven forbid that we should believe in such a way as not to accept or seek reasons, since we could not even believe if we did not possess rational souls.

Three quotes on originality

Posted on by John

Here are three quotes on originality I’ve read recently. I’ll lay them out first then discuss how I think they relate to each other.

C. S. Lewis from The Weight of Glory, as quoted in a blog post by David Rogstad.

No man who values originality will ever be original. But try to tell the truth as you see it, try to do any bit of work as well as it can be done for the work’s sake, and what men call originality will come unsought.

Larry Wall, creator of Perl, in his talk Perl, the first postmodern programming language.

Modernism is also a Cult of Originality. It didn’t matter if the sculpture was hideous, as long as it was original. It didn’t matter if there was no music in the music. Plagiarism was the greatest sin. … The Cult of Originality shows up in computer science as well. For some reason, many languages that came out of academia suffer from this. Everything is reinvented from first principles (or in some cases, zeroeth principles), and nothing in the language resembles anything in any other language you’ve ever seen. And then the language designer wonders why the language never catches on. … In case you hadn’t noticed, Perl is not big on originality.

Paul Graham in the introduction to Founders at Work.

People like the idea of innovation in the abstract, but when you present them with any specific innovation, they tend to reject it because it doesn’t fit with what they already know. … As Howard Aiken said, “Don’t worry about people stealing your ideas. If your ideas are any good, you’ll have to ram them down people’s throats.”

If you strive to be original, you might achieve it in some technical sense, but end up with something nobody cares about. Strive for authenticity and excellence and you’re more likely to do something valuable. But originality isn’t appreciated as much in practice as it is in theory.

Update: See this quote from Twyla Tharp on originality.

Good opening lines

Posted on by John

Its always hard for me to decide the opening line for a paper. Here’s an opening line I ran across recently in a statistics paper.

Imagine we own a factory that produces nuts and bolts.

You had me at hello!

Here’s another great line, taken from the preface to the third edition of Theory of Probability by Harold Jeffreys.

Some points in later chapters have been transferred to the first, in the hope that fewer critics will be mislead into inferring what is not in the book from not finding it in the first chapter.