Hypothesis 0

According to Clancy et al., the CSWA Workplace Climate Survey was designed to test four hypotheses:

1. Female respondents will report more verbal and physical harassment than men.
2. Respondents of color will report more verbal and physical harassment than white respondents.
3. Trainees will report more verbal and physical harassment than those scientists of a higher rank.
4. Women of color experience double jeopardy where they are especially at risk for verbal and physical harassment compared to white women or men of color.

While they do not make the null hypothesis explicit, it is clear that they are testing these against their simple negation. That is, the null to be rejected is that men and women, whites and non-whites, trainees and seniors, will experience equal amounts of verbal and physical harassment.

This null, I want to argue, is not very compelling. To see why, consider what these hypotheses would look like if they were not about the sample (i.e., the "respondents") but about the population (i.e., "astronomers"). Here we need to add some information to capture the wording of the survey that the respondents were responding to, fixing both the situation and the basis of the harassment (I have marked the additions with square brackets):

1. Female astronomers experience more verbal and physical harassment [from other astronomers based on their gender] than male astronomers.
2. Astronomers of color experience more verbal and physical harassment [from other astronomers based on their gender or race] than white astronomers.
3. Astronomers in training experience more verbal and physical harassment [from other astronomers based on their gender or race] than astronomers of a higher rank.
4. Female astronomers of color experience double jeopardy where they are especially at risk for verbal and physical harassment [from other astronomers based on their gender or race] compared to white female or male astronomers.

This, it should be noted, is roughly how the results have been presented to the public by press releases and news coverage. But the importance of turning the hypotheses into statements about astronomers lies in pointing to what we can call the Astronomy Effect on the likelihood of experiencing verbal and physical harassment. Does becoming an astronomer expose you to a particular risk of such harassment? Consider four hypotheses about the general population:

1. Women experience more gender-based verbal and physical harassment than men.
2. People of color experience more race-based verbal and physical harassment than white people.
3. Trainees experience more race- and gender-based verbal and physical harassment than people of a higher rank.
4. Women of color experience double jeopardy where they are especially at risk for gender- or race-based verbal and physical harassment compared to white women and men.

It would be surprising if these statements weren't true in the general population, right? So the implicit null of the CSWA survey was that joining the astronomy community would completely eradicate race- and gender-based differences. Why would we begin there? Why would we not begin with the reasonable hypothesis that becoming an astronomer would reduce your exposure to the risk of harassment, and rising in the ranks of astronomy would reduce it still further? We might then be distraught, as Clancy and Richey have said they were, to learn that it actually has no effect on your chances of being harassed, or, indeed, actually increases it.

Such an effect (which I think is unlikely, but possible) could be explained by the continuing, if shrinking, gender and race disparities in astronomy. If becoming an astronomer increases her exposure to the company of men, she might find her exposure to harassment increase as well. Likewise, by deciding to join the community of astronomers, people of color will generally be exposing themselves to the company of white people. If their baseline experience has been among people of color, they might well experience a change similar to moving from a black to a white community.

My point isn't to argue for or defend any level of harassment. My point is just that a null hypothesis does not have to have a zero value. It just has to suggest a zero effect on the dependent variable of the hypothesized force, which, here, as far as I can tell, is the particular "hostility" that the astronomical community allegedly directs toward women and minorities. Even if astronomers are not particularly hostile to women and minorities, I want to say, we would expect them to experience more gender- and race-based harassment than white men in the same field. It's just that we'd expect the overall level of that harassment to go down when they are at work.

Finally, I would assume that the baseline level of race-based and gender-based harassment that white men face (before going into astronomy) is quite low (almost by definition, you'll note) and might drop to virtually zero in the protected space of the observatory. In a small sample, it's hard to predict what this will do for the statistical significance of the disparity between genders and races. Indeed, I suspect (but I will deal with this in latter post) that the low p-values (often < 0.001) stem from the fact that we are comparing groups that (again, essentially by definition) don't face the relevant form of harassment with those who actually might.* All this seems completely obvious to me and I'm at a loss to understand how an esteemed scientific journal like JGR:Planets came to publish the result in the form it did. Again, I'm happy to hear from people who think I'm wrong. Quantitative analysis isn't my strong suit either.

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*Think, for example, of what would happen if we compared unqualified harassment of men and women in the general population. I think we would find that men get pushed around, as it were, as often as women. They just don't experience this as having anything to do with being men. This survey did not give white men much room to report these experiences. [See this post for more.]