Attitudes, Skills and Knowledge (ASK) is an educational consultiing firm. This month's newsletter features a column by David Oliver that is well worth reading by anybody who has to shape and evaluate another person's performance (that's just about everybody, right?)
[Grant] Wiggins says that feedback is not about praise or blame, approval or disapproval. Good feedback describes what a student [person] did or did not do for the purpose of changing or maintaining a behavior or performance. Robert Marzano and associates concur that effective feedback should provide students [people] with an explanation of what they are doing correctly and what steps they must take to continue to make progress.
Think about how often somebody has told you "Not good enough!" but didn't give you any guidance as to how to improve. Not very motivational, is it?