'I don't know if I'm good at it or not. But I'm certainly willing to do it.'

Wall Street Journal Supreme Court correspondent Jess Bravin sat down with Justice O'Connor to talk about her work as a substitute judge on federal circuit courts. Read excerpts from the interview.

The Wall Street Journal: You were a state judge and a Supreme Court justice for more than three decades. You retired in 2006. Why are you still out there judging?

Sandra Day O'Connor: It's required. Not only that, I believe the requirement includes that the chief justice certify that I've done an adequate amount. And he doesn't know what's adequate, nor do I. I've done a fair amount so I assume it's adequate. It's kept me busy.

WSJ: Isn't this a self-enforcing burden? No one's going to say, "You haven't been judging enough!"

Justice O'Connor: Oh, I don't know. The chief justice has to say it's enough.

WSJ: Does he give you a performance review each year?

Justice O'Connor: He doesn't say whether I've done a good job or not, but he has to say whether in his opinion I've done enough to meet the statutory requirement. I'm sure he doesn't know what that is, because I don't know what that is. I think I've done plenty, but that's my opinion!

WSJ: Okay, you have to do it. But you're obviously very good at it --

Justice O'Connor: Oh, I don't know if I'm good at it or not. But I'm certainly willing to do it. It's been an interesting opportunity for me to see the different circuits and it also makes it