In management literature, there is often mention of two opposite
effects, the halo and the horns effects. In theory, your description
fits the horns effect. In theory, using this "normal" distribution,
many more employees should fall to the lower category as you describe.
In reality, the halo effect usually wins out.
IF I recruited, hired, and trained my employees to be the best, then my
population should be skewed in the high range. But since I don't want
to admit that I didn't do a good job hiring and training, I will pretend
that what I have are "above normal" in fact, "high performers". That
way, it makes me look better. And, if I can get them greater raises,
and my salary in % above them, that means more money for me. The high
subjectivity of the process encourages me to rank me employees in the
high ranges.
In addition, if my employees are in fact low performers, it reflects
poorly on me as a manager. But, if I have to tell them they are poor
performers, it usually sets up a conflict situation for me. again, I am
encouraged to rank them in the high category. This is not to overlook
those managers who take delight in "kicking ass" and beating up on the
poor performers.
Bob
"Dr. Ed Kemery" wrote:
>
> You folks have been talking about a pet peeve of mine for some time -- that
> is, forcing a normal distribution on a group of employees for the purposes
> of appraisal. The fallacy of this approach is that if your employment
> process is doing a good job of identifying, hiring, and retaining quality
> employees, and they are performing to their potential, the forced
> distribution process will mandate that many appraisals will not reflect
> employees' actual performance levels. Most likely, employees will be rated
> LOWER than deserved because the hallowed normal distribution will only
> permit a small percentage of high merit decisions. When struggling to fit
> their ratings to the normal distribution, managers are forced to make
> distinctions that do not really exist. Ultimately, this imposition results
> in a process that is LOWER in validity (job relatedness) because of the
> error of measurement introduced by creating illusory differences.
> Ed Kemery
> University of Baltimore
>
> >-----Original Message-----
> >From: Tim Edlund <
tedlund@MORGAN.EDU>
> >To:
MG-ED-DV@MAELSTROM.STJOHNS.EDU <
MG-ED-DV@MAELSTROM.STJOHNS.EDU>
> >Date: Tuesday, May 02, 2000 12:32 PM
> >Subject: Re: NBA Player Heights
> >
> >
> >This seems clear. It leads to the assumption that a larger proportion of
> >"our" employees fall outside the 2 SD range than is actually the case. IF
> >we have a forced distribution of rewards, then more people (assuming
> >sufficiently large numbers, which is rarely the case) will get the highest
> >rewards than deserve them, and more will get the lowest rewards - which
> >may be no rewards or even negative rewards - such as layoffs, firing, etc.
> >
> >Which brings up another problem - if we use forced distributions to
> >de-select those at the bottom, then those people will no longer be
> >on-board to occupy the bottom, and some of those previously judged to be
> >in the middle range will have to be judged sub-standard the next time the
> >exercise is done. For firms forced to frequently retrench, this issue
> >will continue to exist.
> >
> >An argument for unions, I suppose! They tend to insist on some sort of
> >non-judgemental rule to determine who has to go - such as last in, first
> >out!
> >
> >Tim Edlund, Morgan State University
> >
> >On Tue, 2 May 2000, Robert Bacal wrote: [truncated to save space]
> >
> >> let's see if we can tease out the real life
> >> implications of having a distribution that one assumes is normal but
> >> isn't.
> >>
> >> So let's say we have a distribution at work (on performance or
> >> ability or whatever) that has 77% of people within 2 SD's (we'll
> >> assume it's symetrical for now, that's a test we didn't talk about)
> >>
> >> The company, however is assuming that the distribution is normal
> >> (eg. 68% within the "hump and any other characteristics").
> >>
> >> If the company was handing out rewards based on the normal curve
> >> (which would be inaccurate for them), what kinds of errors (if any),
> >> might occur?
> >>
> >> (I don't know the answer to this -- I should be able to muddle
> >> through it, since it's a logic thing, but my brain is fuzzy right now).
> >>
> >> Anyone?
> >>
> >> What other errors might be made from assuming a normal curve
> >> when one doesn't exist?
> >
> >