Thursday, May 28, 2015

How to do bad science

Here's an instruction manual:
“Slim by Chocolate!” the headlines blared. A team of German researchers had found that people on a low-carb diet lost weight 10 percent faster if they ate a chocolate bar every day. It made the front page of Bild, Europe’s largest daily newspaper, just beneath their update about the Germanwings crash. From there, it ricocheted around the internet and beyond, making news in more than 20 countries and half a dozen languages. It was discussed on television news shows. It appeared in glossy print, most recently in the June issue of Shape magazine (“Why You Must Eat Chocolate Daily”, page 128). Not only does chocolate accelerate weight loss, the study found, but it leads to healthier cholesterol levels and overall increased well-being. The Bild story quotes the study’s lead author, Johannes Bohannon, Ph.D., research director of the Institute of Diet and Health: “The best part is you can buy chocolate everywhere.”

I am Johannes Bohannon, Ph.D. Well, actually my name is John, and I’m a journalist. I do have a Ph.D., but it’s in the molecular biology of bacteria, not humans. The Institute of Diet and Health? That’s nothing more than a website.

Other than those fibs, the study was 100 percent authentic. My colleagues and I recruited actual human subjects in Germany. We ran an actual clinical trial, with subjects randomly assigned to different diet regimes. And the statistically significant benefits of chocolate that we reported are based on the actual data. It was, in fact, a fairly typical study for the field of diet research. Which is to say: It was terrible science. The results are meaningless, and the health claims that the media blasted out to millions of people around the world are utterly unfounded.

The rest of the article explains the details.

This was fraudulent only because the authors of the study knew they were doing bad science. Maybe you think journalists shouldn't be skeptical of such things, but the alternative is to spread misinformation - which they did in this situation.

Also, note that Bohannon couldn't get this study accepted in peer-reviewed scientific journals. That's because other scientists would have checked his research methodology and seen that it was crap.

But he still got it accepted in the 'scientific journal' equivalent of diploma mills, which aren't peer-reviewed and where the only qualification is that your check clears. Actual working scientists wouldn't pay any attention to what they publish, but it would sound authoritative to uninformed laymen.

This is another reason why intelligent laymen should accept the scientific consensus, while being skeptical of sensational claims in the popular media, promoted by celebrities, or pushed by true believers, whether 'scientists' or not. The scientific method includes procedures designed to filter out bad science like this.

That's why scientists do it. (No, it's not to suppress the truth, and you'd have to be incredibly gullible to think otherwise.)

PS. Note that, as PZ Myers points out, there are serious ethical concerns with this whole demonstrate-bad-science idea.

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