I ran across an interview of Peter Sims, author of Little Bets:  How Breakthrough Ideas Emerge from Small Discoveries and it reminded me about some of the difficultes moderators face in testing creative.  If a moderator is not careful, good ideas can be overanalyzed out of popularity by overzealous respondents and/or clients more concerned about the methodology than what is being researched.  

One way to block the creative energy of an idea in a focus group is to use a rigid discussion guide that remains the same group after group after group, even when you've learned something new.  I've never understood why clients want to continue the same questioning within a set of focus groups when you've discovered something new and can build on that new foundation.  Focus groups are not tracking studies. You don't need to keep questions the same in each group in order to analyze the results accurately.  Each group's guide should build on the previous learnings to get a well-rounded understanding of the issues.  You can always check if your hypotheses are working with each new group and adjust the questions accordingly.  The question you want to ask yourself is not so much, 'how do we test these ideas' but rather 'how do we develop them?'  This does not mean that every idea is something to pursue but, with the frame of mind on development rather than test, you are automatically more open to where the idea can lead.

Marketing, advertising and creative professionals should choose a moderator who understands how to protect the life of the idea as well as represent the consumer and I believe both jobs can be done simultaneously.  Protecting the creative simply means not allowing the consumer to take on the role of marketer or creative in judging the creative product.  The consumer's role is to react to the creative - period; and the moderator's job is to understand what caused such a reaction.  

In representing the consumer, the moderator needs to understand the following questions:
Was the intended message interpreted correctly?  
Is the message relevant?
Does the consumer believe it to be true?
Is it compelling?  

Treat new ideas in development like building a fire.  Stoke it, give it oxygen and fuel.   If you over analyze or judge new ideas too early, you'll never get the fire started.

http://www.richerlife.com/2011/09/how-little-bets-lead-to-extraordinary-outcomes/