From: mark@wdcwdc.sps.mot.com (Mark Shaw)
Subject: Re: Survey impartiality (was Re: Profits to Japan?)
Organization: Motorola Western MCU Design Center, Chandler Arizona
Date: Tue, 10 Nov 1992 18:23:23 GMT

In article <1992Nov10.023009.13564@magnus.acs.ohio-state.edu>, jnielsen@magnus.acs.ohio-state.edu (John F Nielsen) writes:
|> Since both of you agree that this was the gist of the theory then. . . 
|> Why does this make CU not very valuable. I think I gave the wrong
|> impression what I said it is the major things that count. What
|> I mean is that the minor things are more subjective are harder
|> to rate.

There is probably some value in trends over a period of years, in which
case it might give you a clue as to what to look for.  However the summaries
do not give the important dollar cost and/or difficulty in repairing the
failure.  Like I said, some people get really snookered on a minor tuneup
that is required every year; while others may may only pay a small amount
every couple of years for a new exhaust system.

CU really needs to quantify the magnitude of costs for maintenance and 
repair.  But I think they even realize that just data would be very
dubious when you consider that most people have trouble with their
simple checkbook.  I prefer to look at long term reports in the variour
auto magazines for real costs over a time/distance.  Autoweek also supplies
the "typical" price for certain repair parts (like alternators, windshields,
etc.) which can be very revealing.

|> Regardless, CU doesn't ask  vague subjective questions regarding
|> did you/did  you not like the car. At least as far as their ratings
|> are concerned. They ask about what was repaired and the cost
|> of the repair. Something not hard to figure out even for biased
|> people. So, even if the effect you speak of exists, how pronounced
|> can it be? How many and what type of repairs do you think are
|> nullified?

I cannot remember what I paid for service last year, can you?  If I go
dig around in my files I can find it.  The point is, who is going to go
to that much trouble to be part of a "volunteer" survey?  If you don't
get EVERY owner of the particular model to respond then the ones who
are satisfied with their car, may not want to bother.  If that is the
case you will only get the frantics (for and against) to spend the time
and effort.   CU's method IS NOT, I repeat, IS NOT statistically sound,
nor factually rigorous.  

|> Also, why would a person buy a car that they knew to be of low
|> quality? 

It's a cost/benefit trade-off.   Not everyone can afford a Mercedes.
Nor are there and infinite supply of quality cars.

|> Why would the Suzuki Samauri, something CU trashed have an excellent
|> reliability rating.

What you keep doing is using this word "reliability" everytime you refer
to their repair "history".  Reliability is measured in mean time to failure
(MTBF) or number of defects over a population (ppm).  Those terms are never
used in the CU ratings.   They are reporting incidents and making a judgement
call on them being above or below average (whatever that is).  It cannot
predict anything about the probability of a failure occurring.  Your 
paradox example above shows just that.

|> As far as I can tell you at least grant that CU can provide a
|> general guide as to how well a car will do.

Are you suggesting that a person can judge the expected quality of
a new car based on the repair incidence of past years?   Not even the
Japanese would agree to that.   The name of the game for the successful
players is to constantly strive for improvements.  It may very well be
that the car with the 5-year record for bad exhausts, finally made a
design/material change that makes their system 2X better than the 
competition.  To assume the future based on the past is pure negative
CU thinking at its best.

|> Do you think the informstion is so biased that one might as well
|> not even look at it?

I don't. And I haven't been burned.  No, take that back, I once bought a
piece of crap that I think CU liked -- a used '75 Honda Civic.  I made
the mistake of assuming that since it was Japanese in couldn't possibly
be bad.   So much for collective opinion and predicted "reliability."

Mark

BTW.  Just once, I wish the consumer advocates would do an analysis on
the realative merits of various consumer magazines :-)  But, that would be
like asking the fox to watch the chicken coop :-(