Honda Car Forum

On Dec 12, 8:49*am, "C. E. White" <cewhi...@removemindspring.com>
wrote:
> "Lloyd" <lpar...@emory.edu> wrote in message
>
> news:72b201f1-4031-4404-b4f0-9ae5961c3c68@v13g2000vbb.googlegroups.com...
> On Dec 11, 3:36 pm, "Mike Hunter" <mikehunt2@lycos/com> wrote:
>
>
>
> > Could they not just continue the statistical MYTHOLOGY they are
> > currently
> > using? To correct the so called 'below average' thing why not simply
> > state
> > the PERCENTAGE of failure rate that is actually what the current
> > ratings are
> > reflecting?
>
> > Come to think of it, that would not work. Subscribers would wise up
> > and no
> > longer subscribe if they realize what CR is showing as a 'list' is
> > actually
> > showing that ALL manufactures vehicles are falling within the
> > standard
> > statistical methodology of the 2% failure rate for ALL manufactured
> > products
> >
> > Why don't you READ CR's explanation of their analysis before
> > spouting
> > off and looking stupid?
>
> http://www.consumerreports.org/cro/c...est/consumer-r...
>
> I have read it and I still believe the little circle over emphasize
> small differences, that may not be statistically valid. In the
> discussion they talk about the average circle representing a failure
> rate of 2.5% (not an actual value, but their example). Do you think
> that a sample size of 100 vehicles is enough so that you can cut
> things that fine (the difference between average and excellent is 2.5%
> and there is "very good in between)? And then consider that the sample
> is not a random sample. People choose to participate. And the only
> people who have that choice are Consumer Reports readers. So the
> people who respond are opinionated, motivated people who like Consumer
> Reports. Don't you suppose they are likely to be biased towards
> agreeing with CR's editorial opinions?
>
> Ed

So you're claiming a CR reader who drives a Chevy is simply going to
report more problems than one who drives a Toyota? Why? And do you
have a shred of evidence to back up this wild accusation?

If you were correct, all the cars low on CR's scoring would be rated
unreliable too, and vice-versa? That's simply not true. Look at the
articles. Or are you claiming readers look at what other readers say
about reliability, and then next year, like sheep, write down the same
things? That's simply ludicrous. And if so, no car would ever change
its reliability, and many do.

"C. E. White" <cewhite3@removemindspring.com> wrote
> "Elle" <honda.lioness@gmail.com> wrote in message
> news:4Ru0l.4052$%z5.3924@newsfe09.iad...
>> "C. E. White" <cewhite3@removemindspring.com> wrote
>>> "Lloyd" <lparker@emory.edu> wrote
>>>> Why don't you READ CR's explanation of their analysis
>>>> before spouting
>>>> off and looking stupid?
>>>
>>> http://www.consumerreports.org/cro/c...ity-faq_ov.htm
>>>
>>> I have read it and I still believe the little circle
>>> over
>>> emphasize small differences, that may not be
>>> statistically
>>> valid. In the discussion they talk about the average
>>> circle representing a failure rate of 2.5% (not an
>>> actual
>>> value, but their example).
>>
>> In what part did you see this mention of 2.5 percent? I
>> see
>> it only in section 4.2, and it says nothing like what you
>> say.
>
> Yes, section 4.2. I expressed myself poorly. In the CR
> example of what happens with small problem rates they use
> the 2.5% average failure rate as an example (which is why
> I said "not an actual value, but their example").

It is not an example. Nor do they call it a "failure rate."
It is a "problem rate."

Section 4.2 does not say anything like what you are saying.

>>> Do you think that a sample size of 100 vehicles is
>>> enough
>>
>> This is the minimum required sample size. If you read the
>> site linked above, it notes that 200-400 cars per model
>> year
>> is usual.
>
> And this is still a very small sample size when you are
> talking about very small actual differences in failure
> rates.

Problem rates. Not when one is trying to establish whether
the differences between two models are statistically
significant.

I think this is a very honest and fair statement by CR:
"While the difference between a [fully colored red circle]
and a [half colored red circle] may be small, a pattern of
several less-than-perfect trouble spots in a brand new car
should be cause for concern and does not bode well for a
model's long-term reliability."

>> I disagree with other points you are making.
>
> Which points are those?

Pretty much all of them, because they are based on the large
errors you made above. IOW, your premise is wrong.

I do not have a problem with anyone calling the samples CR
uses biased, as long as they call nearly all samples used in
any such study biased. CR's survey is what it is. I have not
seen a better survey out there.

Really, CE White, you are entitled to your opinion. I do not
expect you to buy mine. I am responding for others, as an
engineer with publications, advanced degrees, much education
in statistics, and years of engineering experience. Not that
these make me more of an authority. More that others
poo-pooing the CR study are saying they have such
credentials. They're wrong, AFAIC.

On Fri, 12 Dec 2008 08:04:48 -0800 (PST), Lloyd <lparker@emory.edu>
wrote:


>So you're claiming a CR reader who drives a Chevy is simply going to
>report more problems than one who drives a Toyota? Why? And do you
>have a shred of evidence to back up this wild accusation?


Not wild at all. The Toyota Corolla and its Chevy clone often were
rated differently.

On 12/11/08 9:21 PM, in article 43m3k4pkqa3vvlujlh1d13r3a2fsfc8e0h@4ax.com,
"dizzy" <dizzy@nospam.invalid> wrote:

> top-posting troll Mike Hunter wrote:
>
>> Search 'standard statistical methodology' and get back to us, dummy. It
>> can not be stated accurately as a 'list.'
>
> Learn how to quote and post, and then DON'T get back to us, "Mike",
> you top-posting idiot.
>

Oh God, Dizzy's back. Time to update the spam filter.

On Dec 12, 11:27*am, edward ohare
<edward_oh...@nospam.yahoo.com.invalid> wrote:
> On Fri, 12 Dec 2008 08:04:48 -0800 (PST), Lloyd <lpar...@emory.edu>
> wrote:
>
> >So you're claiming a CR reader who drives a Chevy is simply going to
> >report more problems than one who drives a Toyota? *Why? *And do you
> >have a shred of evidence to back up this wild accusation?
>
> Not wild at all. *The Toyota Corolla and its Chevy clone often were
> rated differently. *

"4.7. Why are there sometimes considerable differences in reliability
between "related" or "twin" models?
Some variants of similar vehicles have different reliability results
in our survey. Although you might expect that related vehicles, or
"twin" models, would have very similar reliability histories, there
are a number of factors that can lead owners to have different
reliability experiences with these models.

Some differences can be attributed to different equipment, such as
different transmissions, suspension tuning, or power equipment.

Some related models may be manufactured in different plants. While
their designs might be quite similar, by being built in separate
facilities they may be subject to different manufacturing processes,
such as differences in quality control.

Some model variants that share the same design but have different
equipment level or body style can lead to differences in reliability.
For example, the V6 version of the Chrysler Sebring has below average
predicted reliability, but the 4-cylinder version had average
reliability. The V6 offered more standard equipmentthan the 4-cylinder
and had more power equipment and audio problems. The redesigned for
2008 Chrysler Sebring Convertible has much worse than average
predicted reliability. The convertible body style contributed to more
body hardware and squeaks and rattles in addition to electrical, power
equipment, and audio problems.

These are some examples of factors that may cause seemingly similar
models to have different reliability profiles. We carefully examine
the data for all related models, and if the data show that their
reliability profiles are similar, we will combine their data to yield
more robust results. We believe, though, in the accuracy of our data,
and we have a commitment to report the experiences our subscribers
share with us. In some cases, they report different reliability
experiences with closely related models."

On Fri, 12 Dec 2008 13:46:38 -0800 (PST), Lloyd <lparker@emory.edu>
wrote:

SNIP could haves and might bes

> We believe, though, in the accuracy of our data,


There you have it, Lloyd. They believe.


>and we have a commitment to report the experiences our subscribers
>share with us.


How nice. They're reporting the "experiences of our subscribers", not
the reliability of the cars.


> In some cases, they report different reliability
>experiences with closely related models."


Isn't that a red flag? Apparently "experiences of our subscribers" has
some subjectivity to it.

E. Meyer wrote:

>"dizzy" <dizzy@nospam.invalid> wrote:
>
>> top-posting troll Mike Hunter wrote:
>>
>>> Search 'standard statistical methodology' and get back to us, dummy. It
>>> can not be stated accurately as a 'list.'
>>
>> Learn how to quote and post, and then DON'T get back to us, "Mike",
>> you top-posting idiot.
>
>Oh God, Dizzy's back. Time to update the spam filter.

Aww, then you might miss my "I told you so" about how I was right
about everything, all along. Right about SUV's. Right about the
deficit spending.

Look at where you short-sighted dimwits have gotten us.

In article <ttp5k4dj5g9b2uubiq7ocl27570v6aqqbc@4ax.com>,
edward ohare <edward_ohare@nospam.yahoo.com.invalid> wrote:
> >and we have a commitment to report the experiences our subscribers
> >share with us.


> How nice. They're reporting the "experiences of our subscribers", not
> the reliability of the cars.

How else? The only ones that might have more accurate data - ie from a
larger sample - would be the makers via their dealers, and they're not
going to be honest about such things in public. Quite the reverse - they
lie through their teeth.

It's often the case that those who criticise a consumer body findings on
the reliability of a particular model - ie the one they own - due to a
small sample are basing that criticism on a sample of one...

--
*Beauty is in the eye of the beer holder *

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

edward ohare wrote:

> On Fri, 12 Dec 2008 08:04:48 -0800 (PST), Lloyd <lparker@emory.edu>
> wrote:
>
> >So you're claiming a CR reader who drives a Chevy is simply going to
> >report more problems than one who drives a Toyota? Why? And do you
> >have a shred of evidence to back up this wild accusation?
>
> Not wild at all. The Toyota Corolla and its Chevy clone often were
> rated differently.

Not by much, and when comparably equipped (for part of one model year,
when the Chevy/Geo Nova/Prizm lacked a front anti-sway bar that the
Corolla included) they ranked right next to each other. The same was
true of the Toyota Matrix and its clone, the Pontiac Vibe.

Where did you get your information that said the ratings for the
clones were different?

edward ohare wrote:

> On Fri, 12 Dec 2008 13:46:38 -0800 (PST), Lloyd <lparker@emory.edu>
> wrote:
>
> SNIP could haves and might bes
>
> > We believe, though, in the accuracy of our data,
>
>
> There you have it, Lloyd. They believe.
>
>
> >and we have a commitment to report the experiences our subscribers
> >share with us.
>
> How nice. They're reporting the "experiences of our subscribers", not
> the reliability of the cars.
>
> > In some cases, they report different reliability
> >experiences with closely related models."
>
> Isn't that a red flag? Apparently "experiences of our subscribers" has
> some subjectivity to it.

Or maybe different versions come from different factories. For
example, the early 1990s Ford Escort hatchbacks were made in the US,
but the sedans were from a plant in Hermosillo, Mexico that Ford rated
more highly, and Consumer Reports said that the sedans were slightly
more reliable.

Please cite a car quality survey that's extensive but doesn't reflect
the experiences of the car owners.