The Thinker
The Thinker operates on logic: She loves organization and systems and she likes to see projects through to the bitter end.
How to recognize a Thinker: These people play by numbers and facts. They are logical and realistic, and they will pop any idealistic balloon by citing a similar situation in which someone failed.
How to get a Thinker to cooperate: A Thinker loves systems and organization and solving problems. So when she points out inaccuracies or mistakes, let her know that you understand and will fix the problem. She needs to be reassured that you'll stay grounded in reality and that you'll be very careful about gathering your research.