Clorox Bleach Commercial

The other day when I was watching TV therea was a commercial that came on advertising Clorox Bleach. In the commercial the man was carrying a board that had two white socks tacked on it and one had the Clorox logo under it. He then would ask people on the street which one was brighter. What's wrong with this "experimental" design?

By placing the logo under one of the white socks it ruins the idea of testing people on which sock they really think is brighter because of bias towards Clorox. If someone knows that Clorox is bleach and bleach is suppose to make things brighter then just being exposed the logo ruins your ability to eliminate bias for judging which one is brighter. For good experiments you must eliminate biases.