Andrew Hamada explains the "head in the hallway" technique: ask five random people for quick feedback to make a decision when you don't have much data. It works for general opinions but not when you need specialized expertise.
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If you're used to using data to make decisions, it can be really hard to convince yourself to make a decision quickly without enough data. One of my favorite techniques for overcoming this is called head in the hallway feedback. Imagine that you are a college student living in a dorm, and you're getting ready to go out on Friday night, and you picked out a shirt. You think you look good, but you're not quite sure. You stick your head in the hallway of the dorm, and you ask the first five people that walk by, hey, do I look good in this shirt? And the first five people that walk by all look at you and say, that shirt looks terrible. What are you gonna do? Are you going to say, great, okay, well, there's five data points. I should probably collect several hundred more until I reach statistical significance. Or are you gonna turn around and change your shirt? For most people, the answer is the second. And I think in business you can strive to find similar situations where all you need is a quick signal. Head in the hallway feedback doesn't work if you need opinions from nurses or decision makers at Fortune 500 companies. But if the data that you need can be produced by any normal person, that's a perfect opportunity to use head in the hallway feed.