The doctrine of fair use disfavour merely imitative uses of plaintiffs' works, but favors those in which defendants make what one court called "productive" uses, also known as "transformative" uses. The Supreme Court has stated that the "central purpose" of the investigation into the firs factor of fair use, that is. "the purpose and character of the use, "lies in establishing to the extent to which the user has transformed the work for good social purpose.