The latest fad in performance appraisals is the grading system which was put in place at LANL last year where employees were all rated between 2 and 10 on a subjective basis. This system has landed some of the top companies in the nation in court. At LANL the result was rage though I am not aware of any court cases so far. The system has some inherent flaws as discussed in the article above. Hopefully, management will consider the flaws while creating a new system for next year.
Subjectivity is where prejudice most easily shows.
And unfortunately we all have prejudices. The grading system does not work at all on a group of high performers of a group of low performers because if forces them to be evaluated according to a bell curve. Yes, yes, the bell curve was supposed to be applied across large groups, but, in practice at LANL, we are aware of groups as small as 5 that were forced to meet a bell curve. As we all know the bell curve model only works on a large sample of randomly selected subjects. The employees at LANL were not hired randomly, we presume.