Six Thinking Hats was written by Dr. Edward de Bono. “Six Thinking Hats” and the associated idea parallel thinking provide a means for groups to plan thinking processes in a detailed and cohesive way, and in doing so to think together more effectively.
Although this can be used in groups to aid thinking assigning each person a role has felt restrictive for me. Better example – group assumes all roles at the same time so you move through the different hats together. Also find it useful if going through thinking on my own and avoids falling into favouring your own idea and focussing on yellow and blue hats while missing the others.