The first time i encountered this was during an interview for a large corporation fairly early in my career, and it always stuck with me as one of the best interview techniques i’ve come across, since that interview, its been one of the tools i’ve used regularly to vet candidates that apply.
I’m calling it the Contrarian position. What it involves is, while interviewing the candidate, especially those in strategy and decision making positions, you ask them a fairly obvious question about the market, one where the answer should be pretty straight forward and logical, e.g. ‘why should you use facebook for marketing’ – regardless of the candidates response, take the opposite position and challenge them.
The Contrarian position is really effective as it basically forces the candidate to demonstrate they can hold their position against a senior figure, and in addition can justify their position, with conviction and facts. in other words you can actually SEE the candidates personality when assessing their ability to hold their position, argue their point and analyze the problem.