Working prototypes test better

How quickly can a new product get to the prototype stage and how much of even the prototype needs to be built before you can start to test the results? Try to avoid creating a shadow prototype--build the prototype for production.

With the lean impulse, it's tempting to jump to testing as soon as possible. But what is the difference between testing a feature isolated from its larger context and testing it in its full context? Consider what features from the whole make up the minimum product before you test and before you consider your test results to be actionable.