Kathy Schwalbe* from Minnesota, copies Quentin Fleming
(* Author of Information Technology Project Management,
I'm copying Quentin Fleming, author of PMI's Earned Value Management text. I know I changed my definition of earned value in my second or third edition text after someone asked me a similar question. I say that earned value is an estimate of the value of the physical work actually completed. That way you can actually be ahead of the game, too. I just looked at the new PMBOK, and it didn't seem to address your questions.
Quentin, I think you'd be best qualified to answer Brenda's questions below. Thanks!