“It’s a fact”–what we can learn from Mona Lisa Vito

I have been a fan of “My Cousin Vinny” for yearsmycousin and I must admit to guilty pleasure watching it for the umpteenth time when it does its semi-annual rounds on late night TV. Reading a couple of blog posts recently, I was reminded of my favourite scene where the antagonistic Ms. Vito, acting as an expert in general automotive knowledge,  wins the day by looking at photograph and turns the whole case for the defense…

Vinny Gambini: How could you be so sure?
Mona Lisa Vito: Because there is no way that these tire marks were made by a 1964 Buick Skylark convertible. These marks were made by a 1963 Pontiac Tempest.
D.A. Jim Trotter: Objection, Your Honor! Can we clarify to the court whether the witness is stating opinion or fact?
Judge Chamberlain Haller: [to Lisa] This is your opinion, or is it a fact?
Mona Lisa Vito: It’s a fact!

The full scene is at the bottom of this post….

The first post was from boingboing about the use of experts in understanding the Japanese nuclear event at Fukushima. The point made by the article was that an expert in one field is not an expert in another. In particular, while an expert in risk management can provide valuable insight on a problem of this magnitude to understand what is going on, you really should ask a nuclear scientist.

It has become a pet peeve of mine that we (the media) treat people as experts without ever considering, do they have any expertise in the subject at hand. I even felt sorry for Sarah Palin, when she was thrust in the limelight by John McCain and she was supposed to have all the foreign policy answers. An expert in public speaking does not equal an expert in the constitution, foreign policy or community service.

So what are we supposed to do about all this. This is where the second blog post comes in. Ben Goldacre in the Guardian had an article titled A case of never letting the source spoil a good story where he details various examples of journalists getting it all wrong where a check of the source material would have saved a lot of erroneous ink and spreading of falsehoods. I think his conclusion is right on

Of course, this is a problem that generalises well beyond science. Over and again, you read comment pieces that purport to be responding to an earlier piece, but distort the earlier arguments, or miss out the most important ones: they count on it being inconvenient for you to check. There’s also an interesting difference between different media: most bloggers have no institutional credibility, so they must build it by linking transparently and allowing you to double-check their work easily.

But more than anything, because linking to sources is such an easy thing to do and the motivations for avoiding links are so dubious, I’ve detected myself using a new rule of thumb: if you don’t link to primary sources, I just don’t trust you.

So the moral of the story is, if the article or blog post that  you are reading has no links to primary sources – then it is just opinion not fact.

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