Another tool that can prompt you to identify your assumptions is the Business Model Canvas. Students who take one of Steve Blank’s entrepreneurship classes at Stanford, UC Berkeley, or online at Udacity begin by sketching out a business model canvas for their business idea and updating it each week based on what they’ve learned. Most organizations I’ve talked with use the canvas more as an inspiration than something to religiously update each week.

If you’re new to customer development, the canvas is a helpful reminder that you’ve likely made assumptions about a number of areas beyond just your product and primary customer. The type of person who experiences the problem—that’s who you need to talk to. The type of problem that they’re experiencing—that’s the what, how much, and when that you’ll need to find out. The type of task or constraint— that’s the why that you’ll need to understand. You want to make each learning cycle as rapid as possible. Each time you’re wrong, you’ll learn a little bit about why you were wrong, which helps you make a more educated guess the next time. Write down your hypotheses and save them. You’ll be referring to them again later.

You probably identified a fairly broad audience, such as moms or working professionals. That may represent the audience that will eventually be interested in your product. But anyone familiar with the technology adoption lifecycle knows that not all of these people will be ready to buy or use your product on day one. You need to find and focus on those day one people, found on the left side of the innovation adoption lifecycle.