Answer:
Be positive, but constructive. A team should respond with an enthusiastic, but honest, analysis. A "thank you" should start the conversation. Questions should be respectful and ideas offered on how to make the idea even better. Avoid "this won't work, that was MY idea, or that won't work" responses, but still be honest in an appraisal. The goal is to encourage ideas and not judge in the meeting. Focus on how to make it better, and the contributor will feel comfortable in offering future ideas.
Step-by-step explanation:
A major barrier to innovation is fear of rejection. Really innovative ideas can be radical, and the initial reaction might be to denigrate the concept and get a laugh. But that blocks the free discussion of novel ideas. Imagine if you had proposed to mail DVD's to homes rather than operate stores, in the early days of DVD acceptance. If your Netflix team had laughed at the idea, you might have taken it it Blockbuster and made a fortune. But it the Netflix idea team responded with "Wow. Interesting. Do you really think people will mail them back?," then the whole team would have joined in with ideas on how to make the idea work. Be positive, but constructive.