The fallacy of hypothesis testing?

Kjetil Halvorsen sends along this article by Irene Pepperberg:

I’ve begun to rethink the way we teach students to engage in scientific research.

I [Pepperberg] was trained, as a chemist, to use the classic scientific method: Devise a testable hypothesis, and then design an experiment to see if the hypothesis is correct or not. And I was told that this method is equally valid for the social sciences. I’ve changed my mind that this is the best way to do science. I have three reasons for this change of mind.

First, and probably most importantly, I’ve learned that one often needs simply to sit and observe and learn about one’s subject before even attempting to devise a testable hypothesis. What are the physical capacities of the subject? What is the social and ecological structure in which it lives? Does some anecdotal evidence suggest the form that the hypothesis should take? Few granting agencies are willing to provide support for this step, but it is critical to the scientific process, particularly for truly innovative research. Often, a proposal to gain observational experience is dismissed as being a “fishing expedition”…but how can one devise a workable hypothesis to test without first acquiring basic knowledge of the system, and how better to obtain such basic knowledge than to observe the system without any preconceived notions?

Second, I’ve learned that truly interesting questions really often can’t be reduced to a simple testable hypothesis, at least not without being somewhat absurd. “Can a parrot label objects?” may be a testable hypothesis, but actually isn’t very interesting…what is interesting, for example, is how that labeling compares to the behavior of a young child, exactly what type of training might enable such learning and what type of training is useless, how far can such labeling transfer across exemplars, and….Well, you get the picture…the exciting part is a series of interrelated questions that arise and expand almost indefinitely.

Third, I’ve learned that the scientific community’s emphasis on hypothesis-based research leads too many scientists to devise experiments to prove, rather than test, their hypotheses. Many journal submissions lack any discussion of alternative competing hypotheses: Researchers don’t seem to realize that collecting data that are consistent with their original hypothesis doesn’t mean that it is unconditionally true. Alternatively, they buy into the fallacy that absence of evidence for something is always evidence of its absence.

I’m all for rigor in scientific research — but let’s emphasize the gathering of knowledge rather than the proving of a point.

This makes sense to me, but my research is on the descriptive side; I imagine many of my social science colleagues could present a defense of hypothesis testing. (Just to be clear, I think we’re talking here about the idea of posing and testing hypotheses, not the textbook statistical methods called “hypothesis testing.” The hyp testing that Pepperberg is talking about could just as easily be done using confidence intervals or whatever; her real distinction, I think, is between studies that are exploratory and studies that are designed to test particular scientific theories.

6 thoughts on “The fallacy of hypothesis testing?

  1. I agree. I call what Pepperberg criticizes white-bread science — science that includes hypothesis testing (pure, as white bread is pure) but excludes the gathering of observations on which to base hypotheses.

  2. "what is interesting, for example, is how that labeling compares to the behavior of a young child, exactly what type of training might enable such learning and what type of training is useless, how far can such labeling transfer across exemplars"

    You could easily devise testable hypotheses on all of these questions.

    More generally, I don't know about chemistry, but in sociology there's lots of exploratory work – most qualitative studies are exploratory and there is exploratory quantitative research, too, as pointed out by Hadley.

  3. She hits on something that several people (e.g. Karl Popper) criticised positivist scientists for. You shouldn't just *test* hypothesis, but try to falsify. This would resolve "lining up" theories to experiment. It is also sound since "confirming" by experiment doesn't prove a theory is true, but falsification does show that it is wrong.

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