Running Lean: Iterate from Plan A to a Plan That Works (Lean (O'Reilly))

by Ash Maurya

Your initial goal is to get a strong signal (positive or negative) that typically doesn’t require a large sample size. You might be able to do this with as few as five customer interviews.[12] A strong negative signal indicates that your bold hypothesis most likely won’t work and lets you quickly refine or abandon it. However, a strong positive signal doesn’t necessarily mean your hypothesis will scale up to statistical significance; nevertheless, it gives you permission to move forward on the hypothesis until it can be verified later through quantitative data. Validating hypotheses in this way — first qualitatively, then quantitatively — is a key principle we’ll see applied in various stages throughout this book.