Human factors specialist
The most important fundamental is the why. Without knowing why you’re doing what you’re doing, there will be no real story to tell.
Making bets based on insights from observed human behavior can be far more effective that basing bets on bad surveys. So go forth, be better, and be careful about your data gathering. The most measurable data might not be the most valuable.
…y again and again, and will never tire of repeating, never ask people what they like or don’t like. Liking is a reported mental state and that doesn’t necessarily correspond to any behavior.