This document discusses paper prototyping and its benefits for early-stage usability testing. It recommends creating a paper prototype to test assumptions about a product or service design before launching. A prototype allows validating ideas and iterating on the design through user tests. Paper is a cheap and accessible material for prototyping, allowing anyone to draw a prototype and get feedback. The document provides instructions for developing a paper prototype, finding test users, conducting qualitative user interviews, and refining the design based on the feedback.