Q. Are you better off sticking with one medium over another when seeking expert advice, for example newspapers over the Internet?
A. The simple answer is no. Lousy expert findings are everywhere. I'll just pick on the New York Times, which of course is a wonderful publication with some of the world's best journalists. Still, most of what they publish will not hold up. This is because most of what's published in medical journals turns out to be wrong. But I think we need to be especially cautious on the Internet, which has some of the best expert advice out there, and some of the worst. And, unfortunately, search engines like Google are more likely to take you to the bad stuff.
A. The bad stuff tends to be especially popular. And Google tends to bring you to the popular expert advice. But even if people are looking at the very best sources, the medical journals themselves, they're still going to end up with mostly bad expert findings.
Q. Is there any kind of "batting average" that tells you how accurate a medical journal is?
A. No. You run into a whole new set of problems when you try to keep score. The way the medical field itself measures how experts do is by how often they're cited. But this turns out to be a terrible way of doing it. Some findings that turned out to be completely fraudulent are some of the most highly cited findings in history.
Q. Are other kinds of expert advice more reliable?
A. Obviously, older people are more vulnerable to bad financial advice. And financial advice is, as a rule, the most terrible advice we see out there, except for the somewhat conservative, old-fashioned advice that we've all heard a million times: Have a diversified portfolio and don't try to beat the market. That's the most boring advice in the world, and it has held up decade after decade while almost every other kind of financial advice ultimately falls flat.
Q. In your book, you describe your mixed experiences with online help forums. How do you distinguish between the good and bad advice offered by ordinary people online?
A. I really caution against going online, looking at what some people say in a forum and taking it as the truth. I've seen some terrible examples of bad information about prescription drugs or food or exercise that could actually be quite damaging. It's important to go online and look at many, many different sources to develop a sense of who's probably got it right and which stories seem really fishy.
Q. Have you seen any evidence that older experts are wiser than others?
A. You often get some of the very best and very worst advice from more senior experts. Within science, people later in their careers are often freed from the pressure to publish. They already have tenure. Their careers are pretty much settled. So they're not forced to seek these kinds of exciting findings that turn out to be wrong. On the other hand, having become unmoored from having to worry about the opinions of their fellow experts, some will go off on wild tangents. So I do not recommend judging people solely on the basis of age.
Art Dalglish is an editor and writer based in Maryland.