Values of OK may range from 1% of the final version to 80%; the real test is if the prototype advances your understanding of customer needs by triggering additi

Values of OK may range from 1% of the final version to 80%; the real test is if the prototype advances your understanding of customer needs by triggering additional insights through conversation. If you are not surprised you are not learning and if you are avoiding conversations for fear of failure you are learning much more slowly than you could by taking some prudent risks.