Biased Tests

[cn: Bayesian math]

Suppose that I create a test to measure suitability for a particular job. I give this test to a bunch of people, and I find that women on average perform more poorly. Does this mean that women are less suitable for the job, or does it mean that my test is biased against women?

Psychologists do this all the time. They create new tests to measure new things, and then they give the tests to a variety of different groups to observe average differences. So they have a standard statistical procedure to assess whether these tests are biased.

But I recently learned that the standard procedure is mathematically flawed. In fact, rather than producing an unbiased test, the standard procedure practically guarantees a biased test. This is an issue that causes much distress among psychometricians such as Roger Millsap.

Following Millsap, I will describe the standard method for assessing test bias, sketch a proof that it must fail, and discuss some of the consequences.

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Linkspam: June 10th, 2017

Japan’s rising right-wing nationalism – I recently discovered Vox’s youtube channel, which was especially informative on foreign policy and politics. (Although, I know so little about foreign politics that they don’t have to be that good to teach me something new.) This video is about right-wing nationalists in Japan, whom I immediately hate. They’re the equivalent of neo-nazis, and the rising sun flags are like confederate flags.

On a somewhat related note, why aren’t more people talking about Mindanao (southern Philippines)?  The military clashed with a terrorist group in the city of Marawi, and president Duterte declared martial law in all of Mindanao.  This is very troubling for a number of reasons.

Confusing Intelligence with Goodness – Sara talks about the tendency in American culture to strongly associate intelligence with goodness, and observes that this is not true in Chinese literature.

There have been some attempts in social justice spaces to stop using the word “stupid” because it’s ableist.  But the more I think about it, the more I think this is the wrong approach.  Tabooing a bunch of common words is difficult, and doesn’t address the root problem.  It’s the whole cultural association between cognitive ability and goodness.  BTW, yes I am aware that “stupid” is used in the title of a link in this linkspam, and no I will not comment on that further.

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Disclosure in arguments

[cn: that’s disclosure as in disclosure of rape]

[This is not a response to anything I’ve seen recently.  In fact, it’s a repost of something I posted to Tumblr a while ago.]

I feel like I’ve seen a lot of arguments, where things escalate, and then one person says that they are a victim of rape.  It’s basically a way of saying that they speak with some authority on the topic of discussion.  And then the person on the other side says they, too, are a victim of rape.  And somehow this doesn’t magically clear up any disagreement or stop people from yelling at each other.

The sad fact is that rape is terribly common, especially among women, queer people, and POC, and especially intersections thereof.  In queer spaces, any given argument is relatively likely to be between two people who have each been victimized in some way.

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An activist perspective on gender studies

Another note on that “Sokal-style hoax” on gender studies (see my post, or School of Doubt)…

Although I will come to the defense of gender studies against the sorriest excuse for a hoax I have ever seen, I don’t like gender studies that much. I would never claim that the whole field is pathological–that is not in evidence. But I have read some gender studies papers, and have not been generally impressed with them.

Yes, I have, as a physicist, read gender studies papers. And I didn’t select papers by following right-wing news sources that intentionally cherry-pick the most ridiculous examples. No, I read gender studies papers as part of my work as an asexuality activist. Back in the day, my other blog hosted a journal club on academic asexual studies.  Asexual studies are very cross-disciplinary, including psychology, sociology, history, linguistics, law, and… gender studies!

The short version: Gender studies papers often say stuff that activists already know, or already know is wrong. I am not sure what advantage gender studies provides over, say, blogs.

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Origami: Tsuru Rose

Shown: a paper crane, but the back of the crane is a four-petaled rose

Tsuru Rose, or Rose Crane, by Satoshi Kamiya

Instructions for this model are freely available online, for instance see this video.

This is a neat model that combines ideas from traditional origami, and origami tessellations.  (I last talked about tessellations here.)  You start out by folding a “rose” right in the center of the paper.  The rose isn’t a tessellation, but I believe that in principle it could be turned into one if you repeated the rose infinitely.  But here we just have one rose.  Then we fold the rest of the crane around it.

By the way, there’s a trick to making those wings curve so smoothly.  I press the wing against a toothpick (the side, not the point).  Then I slide the toothpick along the wing several times until it curls.

Any ace writers?

I almost forgot to mention, my other blog The Asexual Agenda, is currently looking for contributors. We’re a group blog targeted at asexual-spectrum readers.

If that interests you even a little, please consider applying! There are details here, and the deadline is next Monday, June 5th. We don’t get that many applicants, so your chances are fairly decent.

How peer review works

Even if you’ve never been involved in scientific research, you’re probably aware that it involves a process called “peer review”. I want to take a minute to explain how this actually works. This is based on my personal experience, although I think much of it generalizes to other academic fields, including those outside of science.

1. Sending to referees

It starts with the submission of a manuscript to a journal. A lot of work has already gone into the manuscript, including input from collaborators and colleagues, but this is where peer review formally begins.

The journal assigns the manuscript to an editor, and then the editor chooses a few (usually 3) referees to look at the paper. Now, choosing referees can be quite difficult, because they need to be close enough to the field that they can understand and critique the manuscript. In fact, it’s common for referees to decline, because they think the manuscript is too far outside their field. And yet, referees can’t be so close that they’re direct competitors. Authors typically provide a list of competitors to the editor to avoid conflict of interest (or even worse, theft of ideas). But editors aren’t required to follow this advice, and authors never know because they don’t know the names of the referees.

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