### Can someone please translate this bizarre critique of psychological testing, or frequentist statistics, or all of the social sciences, or Plato, or something?

- Posted by Paul Gowder on July 19th, 2009 filed in philosophy, psychology, stupidity
- 2 Comments »

Some psychology professor on 3QD apparently thinks that psychological testing is “not scientific” because of the assumption of normally distributed data. Or something.

The strangest bit is a bunch of extremely confusing (and, I suspect, confused) stuff about the central limit theorem not counting because it’s a “tautology.” (I mean, of course it’s a tautology in some sense, since it’s a bloody mathematical proof — but it’s an informative tautology in that it doesn’t premiss the presence of normally distributed data, so what’s this guy’s problem?)

A reader commented, in Part 1 of this article, on my observation that the normal curve is not a representation of nature, by saying I should look up the Central Limit Theorem (CLT). The CLT states that the distribution of means from a very large number of random samples will tend to be distributed normally. Here’s the problem with that comment. The CLT is part of the larger statistical theory, a tautology, that forms the basis for PTT. Since every statement of a tautology is always true, the reader was trying to prove his assertion of the ubiquity in nature of the normal distribution, by asserting another element of the same tautology. That which is tautologically true, cannot be assumed to be a result of empirical discovery, no matter the common sense appeal, long time use, or the prestige of the author(s), and the sales of their books.

In fact, the whole essay is full of this seemingly-incoherent **tautology!** screaming.

Sometimes we copped a reprieve by using an F-distribution because it was more robust in the face of non-normal distributions. Where did we get the notion of F-distributions being robust? You guessed it. It came from the same tautological statistical theory as the Central Limit Theorem.

I’m not as familiar as I’d like to be with any real debates (to the extent there are any) about the normal assumption, so if there is anything real underneath here, please do clue me in. As far as I can tell, however, this guy just sees a theorem and concludes that any statistical method derived therefrom is a tautology and therefore not science. Maybe it’s just a weird brief for bayesianism rather than frequentism? (Except, of course, that bayesian statistics uses proofs too, and if he doesn’t like the normal distribution how does he feel about all the creepy stuff with priors?)

…

Ah-ha. I just looked at part 1. It *is* a weird brief for bayesianism:

This is the first in a planned series of articles with the frontispiece title, “Psychological Science:”. To give you an idea of other topics that may develop, here are a few working titles. “Sigmund Freud, a Personal and Scientific Coward”, “Classical Inference, Bad. Bayesian Inference, Good”, and “Fighting Over Combat Related PTSD”.

Part 1 also contains the what has to be the worst possible argument against the theory of forms. It’s worth reproducing in its entirety:

The problem started with Plato, and maybe Socrates

Do you see what just happened? We have just stepped into Plato’s (c. 428 BCE – c. 348 BCE), and maybe Socrates’ (c. 469 BCE – c. 399 BCE), World of Ideal Forms, or World of Ideas. Is this bad? You bet it is. From a scientific point of view, PTT stepped in a big pile of dodo, two piles to be exact.

Let’s look at Plato’s Forms or Ideas. Plato proposes two realities: that of the sense or experiences which are subject to change; and that of the unchanging essences in the World of Ideal Forms. In the world of our experiences, we encounter kitchen tables, coffee tables, wooden tables, tables constructed from FedEx boxes, and so many other tables. Each of these expressions of a table in the world of experience, actually partakes of the reality of Tableness from the World of Ideal Forms. For Plato this was not a metaphor. It was as real as real can be. The World of Ideal Forms was so real that it was the ultimate reality, or at least the home of many ultimate realities. A draftsman’s table did not so much partake of the Ideal Form of Tableness, as the Ideal Form of Tableness infused the world of experience. Another way of saying this is that the Ideal Form of Tableness acted upon the world of our senses. Tableness was real and it had power.

Ideal Forms were not limited to those that could yield tangible expressions (like tables) in our sensory world. The World of Ideal Forms was populated, also, with immutable principles and attributes like Justice and Beauty and Intelligence and Depression. These principles acted upon the world of experience and were expressed in our things, and our institutions. The State, properly organized, was the highest expression of Justice in the world of experiences. Thomas Aquinas, proved the existence of the soul and the afterlife with the argument from Justice. In short, since we see an incomplete expression of Justice in our daily lives, and since Justice is real and acts upon God’s creation, then scores must be settled and ledgers must be balanced somewhere other than in the world we experience. Aha! Therefore, there is an afterlife. Aha!, again. The afterlife must be populated by souls so that Divine Justice can be visited upon something that outlasted decayed flesh. British humor captured this nicely with an Anglo-Saxon St. Peter. “English souls up this way. The French, down there, please.”

That’s it. That’s his entire discussion of Plato. He then proceeds to write as if he’s shown that a theory that assumes the existence of forms is false and/or dumb and/or unscientific. As far as I can tell, the whole *argument* from this proposition is the guilt-by-association from Aquinas. For that, he’s earned the “stupidity” category.

(Naturally, there is no argument at all for the claim that the assumption of latent variables entails some kind of Platonism about psychological traits. He just asserts it.)

My prediction: he’ll soon plunge into a discussion of theory-ladenness and claim that his preferred method of doing science can escape it.

How very odd.

July 21st, 2009 at 12:49 pm

“we can’t all be sublime”

-paul gowder

fuck me. not in a good way.

July 21st, 2009 at 2:15 pm

I think the main method this person has to explain things is trough hypotesis proof from probability area. The secondaries ones all belong to probability area too Therefore she went and tried to expalined it with that metodology she knows, with has nothing to do with what she tries to proof, it is like she is trying to fit a square and a round peg.

Please do not let this person be a teacher cause nowbody will ever learn anything