karlkrandall@sbcglobal.net wrote:
> On Fri, 23 Mar 2007 16:43:19 GMT, John Navas
> <spamfilter0@navasgroup.com> wrote:
>
>> In fact I've pointed to JDPowers as the best available data, which shows
>> relatively small differences between carriers, on the order of the
>> sampling error.
>
>
> Not nationally. Only in certain markets.

The advantage of the Consumer's Union data is two-fold. First, they used
a much larger sample size, hence the margin of error is lower. Second,
they broke down the data into much smaller geographic units than J.D.
Power. With J.D. Power, they ranked Qwest and Verizon significantly
better than the other carriers in the West region, but the West region
is huge, literally half the area of the lower 48, with many variations
within the region.

Even though the Consumer's Union survey only targeted Consumer's Reports
subscribers, any differences between subscribers and the population at
large cancelled out, since subscribers were only rating their own
carrier's quality.