Designing for users is a tough job. To optimize our designs and strategy, UX professionals frequently turn to concept/site testing. The problem is that most design strategy and testing thinks in terms of input → output. We provide input, users perform a desired response (click-through, purchase, content creation). How to break out of this mold? Perceptual control theory (PCT) assumes that all output is based on the ultimate goal of improved perceptual input. If you replace "input" in the above with "experience," you'll see the direction this discussion is going... Cross-posted from uxtraordinary.com, my not-so-secret UX blog-in-progress. Original posting: August 2009.