What a scientist knows about science (or, the limits of expertise).

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This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


In a world where scientific knowledge might be useful in guiding decisions we make individually and collectively, one reason non-scientists might want to listen to scientists is that scientists are presumed to have the expertise to sort reliable knowledge claims from snake oil. If you're not in the position to make your own scientific knowledge, your best bet might be to have a scientific knowledge builder tell you what counts as good science.

But, can members of the public depend on any scientist off the street (or out of the lab) to vet all the putative scientific claims for credibility?

Here, we have to grapple with the relationship between Science and particular scientific disciplines -- and especially with the question of whether there is enough of a common core between different areas of science that scientists trained in one area can be trusted to recognize the strengths and weaknesses of work in another scientific area. How important is all that specialization research scientists do? Can we trust that, to some extent, all science follows the same rules, thus equipping any scientist to weigh in intelligently about any given piece of it?


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It's hard to give you a general answer to that question. Instead, as a starting point for discussion, let me lay out the competence I personally am comfortable claiming, in my capacity as a trained scientist.

As someone trained in a science, I am qualified:

  1. to say an awful lot about the research projects I have completed (although perhaps a bit less about them when they were still underway).

  2. to say something about the more or less settled knowledge, and about the live debates, in my research area (assuming, of course, that I have kept up with the literature and professional meetings where discussions of research in this area take place).

  3. to say something about the more or less settled (as opposed to "frontier") knowledge for my field more generally (again, assuming I have kept up with the literature and the meetings).

  4. perhaps, to weigh in on frontier knowledge in research areas other than my own, if I have been very diligent about keeping up with the literature and the meetings and about communicating with colleagues working in these areas.

  5. to evaluate scientific arguments in areas of science other than my own for logical structure and persuasiveness (though I must be careful to acknowledge that there may be premises of these arguments -- pieces of theory or factual claims from observations or experiments that I'm not familiar with -- that I'm not qualified to evaluate).

  6. to recognize, and be wary of, logical fallacies and other less obvious pseudo-scientific moves (e.g., I should call shenanigans on claims that weaknesses in theory T1 count as support for alternative theory T2).

  7. to recognize that experts in fields of science other than my own generally know what the heck they're talking about.

  8. to trust scientists in fields other than my own to rein in scientists in those fields who don't know what they are talking about.

  9. to face up to the reality that, as much as I may know about the little piece of the universe I've been studying, I don't know everything (which is part of why it takes a really big community to do science).

This list of my qualifications is an expression of my comfort level more than anything else. It's not elitist -- good training and hard work can make a scientist out of almost anyone. But, it recognizes that with as much as there is to know, you can't be an expert on everything. Knowing how far the tether of your expertise extends is part of being a responsible scientist.

So, what kind of help can a scientist give the public in evaluating what is presented as scientific knowledge? What kind of trouble can a scientist encounter in trying to sort out the good from the bad science for the public? Does the help scientists offer here always help?

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