Performance review proponents say the way it is done matters most[the broken link was removed] (based on reaction to: Performance appraisals get low marks[the broken link was removed]):
Good execution of performance appraisal is not the solution. More people are realizing that improving how performance appraisal are done is an attempt to do the wrong thing better. If you insist on doing the wrong thing, I suppose you might as well do it better but how about just not doing the wrong thing at all? What should be done? See: Performance Without Appraisal and read chapter 9 of The Leader’s Handbook.