The phrase "I know it when I see it" is a colloquial expression by which a speaker attempts to categorize an observable fact or event, although the category is subjective or lacks clearly defined parameters. The phrase was used in 1964 by United States Supreme Court Justice Potter Stewart to describe his threshold test for obscenity in Jacobellis v. Ohio. In explaining why the material at issue in the case was not obscene under the Roth test, and therefore was protected speech that could not be censored, Stewart wrote:
Yoeli Childs: I’m going to be able to be a pro for a really long time, but I only have one more year to do something special here. I owe it to this school. I owe it to these guys over here, my teammates, to come back and do something amazing. I just want to go all out and make something special happen for BYU.