Vox article on Debunking, avoiding The Backfire Effect

[Pete Tar]

Some good advice we should keep in mind.

http://www.vox.com/2014/12/22/7433899/debunk-how-to
Lewandowsky: The moment you get into situations that are emotionally charged, that are political, that are things that affect people’s fundamental beliefs — then you've got a serious problem. Because what might happen is that they’re going to dig in their heels and become more convinced of the information that is actually false. There are so-called backfire effects that can occur, and then the initial belief becomes more entrenched.
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It’s very difficult. A lot of this stuff is about cultural identity and people's worldviews. And you've got to take that into account and gently nudge people out of their beliefs. But it’s a difficult process.
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There’s some evidence that you can avoid that if you ask people to tell us [about] an occasion when you felt really good about your fundamental beliefs in free enterprise (or whatever is important to the person in question). Then they become more receptive to a corrective message. And the reason is that it’s less threatening in that context. Basically, I make myself feel good about the way I view the world, and then I can handle that because it’s not threatening my basic worldview.
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Now, the trick appears to be that you’ve got to get people the opportunity to deal with information in great depth. If you have a situation like a classroom where people are forced to sit down and pay attention, that’s when more information is helpful. There's a lot of evidence of this in educational psychology.

Now the problem is in a sort of casual situation, people listening to the radio or having a superficial conversation — that's where the information deficit model doesn’t apply. And superficially just throwing information at people probably will make them tune out.
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There’s a couple of things I can suggest. The first thing is to make people affirm their beliefs. Affirm that they’re not idiots, that they're not dumb, that they’re not crazy — that they don't feel attacked. And then try to present the information in a way that’s less conflicting with [their] worldview.
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However, there's plenty of evidence that in a casual context — turning on the TV or whatever — you can dilute the message by putting too much information in it. This whole information-overload issue is more critical in a more casual context. And that's always important.

Content from External Source

It also mentions The Debunking Handbook.
http://www.skepticalscience.com/Debunking-Handbook-now-freely-available-download.html