During product discovery, we create prototypes to answer questions. Questions like: what size should the product be to fit nicely into our target user’s grip? Should our shopping cart software split the checkout process into multiple pages? Would our users find value in a version of our app ported to Android tablets?

Since the goal is to answer questions, we build prototypes as quickly and cheaply as possible. A prototype is not a carefully-engineered artifact, meant to stand the test of time. Instead, prototypes are disposable, to be thrown away once their purpose has been fulfilled.

Throw away failures and successes

A completed prototype might be considered a failure (or “falsified”) for any number of reasons. The designer may feel that the design is not sufficiently useable and doesn’t see any obvious tweaks to improve it. The engineer got it working using metaphorical duct tape...

In product discovery, our goal is to test many ideas with real users. The faster we test each idea, the more ideas we test. And the more ideas we test, the better our chances of discovering a great product opportunity.

Building and launching a finished product is the slowest, most expensive way to test an idea. So instead, we’ll use a technique known as prototyping, which lets us quickly and cheaply make our ideas real, and allow us to test those ideas with users.

What is prototyping?

A prototype is a rough approximation of what a finished product could be. Prototyping is the process of creating that approximation.

If you’ve ever hung a picture on your wall, you’ve made a prototype. “How does this look?” you asked, holding up the picture. “A little to the left,” your spouse or roommate says. This is a prototype: it looks very similar to the end product, but you try out variations...