Once we know the specifications for our target product, we need some ideas to meet these specifications. In fact, all we really need is one good one. Finding this idea is sometimes discussed by reference to the children's fairy tale, “The Frog Prince.” You will remember the story: a somewhat vain princess who is walking in the woods promises her hand in marriage to a frog in return for some simple service. The frog performs the service and then shows up to claim his bride. The distraught princess submits ungraciously and then is astonished to discover that, after she kisses him, the frog turns into the prince of her dreams. Freudian psychoanalysts have enjoyed interpreting this story.

For us, the story is the antithesis of product design. The chance of our beginning with one frog of an idea and making it into a prince is remote. Our chance of success is much greater if we can screen a large number of ideas. In terms of the fairy tale, we need to behave like a more modern princess, and kiss a lot of frogs. Exactly how many if we want to find a prince? While estimates in different businesses vary, most experienced product developers suggest we need around one hundred ideas to find one winner. We need to kiss one hundred frogs to find one prince.