Prototypes are an inexpensive way to quickly test to what degree your Minimum Feature Set will solve a customer’s pain. The virtual prototype is the easiest, fastest, and cheapest prototype you can build. And since you want to learn about your solution hypothesis as quickly and as cheaply as possible, you should start with the virtual prototype. A virtual prototype allows you to get quickly into the field to test and gather feedback rather than spend large amounts of time and money to build an unproven product. It keeps your flexibility high and your commitment to costs low.
Take a look at the table below. The purpose of the virtual prototype is to allow customers to react to a concept (your idea that solves their pain). Notice that you're not worried about customers reacting to the details of the concept yet, just the general concept. For that reason, your virtual prototype doesn't need functionality; it only needs an explanation of what your solution would look like or do. An example could be drawings or diagrams created on paper or Microsoft PowerPoint slides. They can simply explain the concept without requiring the customer to interact with, handle, or navigate through the product.
The results of the Virtual Prototype Test should provide you deeper validation of the customer pain, initial validation of the solution, and plenty of insights and surprises. If the virtual prototype fails to solve the customers' pain, you can go back to the Big Idea Hypothesis and re-evaluate the pain and the solution. If the virtual prototype proves to solve the customer pain sufficiently, you can then move on to building and testing an actual physical prototype with customers (The Prototype Test will be covered in Unit 7).
(See Nail It Then Scale It, pg. 102)