Invite Honesty and Openness
Introduce your prototype as a work in progress. Make it clear that the development of your idea is still in progress, and that based upon feedback of testers, you will continue to make further changes and improvements to the prototype.
Present all concepts with a neutral tone. Don’t be defensive or sell your idea—listen to all feedback and take notes both on the positive and negative comments.
Adapt on the Fly
Encourage participants to build on the idea, and revise the prototype as you go. Be ready to eliminate or change parts of the idea.