Don't do focus groups
There are other more accurate ways to sample a population. The cost of using a fake focus group to manipulate a population isn't only high, it takes a very specialized moderating skill to pull it off. Oh, and if you get caught, it could become a career ending scandal. It is simply too easy for focus groups to generate misleading or totally inaccurate results and this Fox News attempt showcased this in spades.
In this day and age it is almost impossible not to corrupt a focus group, we all are simply too surrounded by technology now, I wouldn't use one for analysis particularly in a predictive way and I'd always back it up with some kind of validating study if we were looking at historical behavior. But my general and far easier to follow advice is don't do focus groups and don't rely on the results that come out of them.
Of course the real interesting result in all of this was that Carly Fiorina was the biggest beneficiary of this event, largely because she was the best prepared to take advantage of it. Not bad for the one tech exec running for the office. It is interesting to note she is likely also the only candidate, because of her marketing background, who really understands the dynamics I'm talking about.
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