The Official Nov. 2009 NPD Thread Data covers Nov 1-28 comes @ 6:30 PM EST

[binary solo]

Triple Chix said:

binary solo said:

There should be a modest upward adjustment for 360.

The 360 was under tracked by 100+K...  That is not a modest upward adjustment.

Are you talking about the maximum possible discrepancy between 2 estimates? You think the reported discrepancy is the definitive error margin, and the error is solely on the part of the lower of the 2 estimates? Those are bold claims indeed.

I'll certainly accept that VGC 360 numbers for Americas could be low by up to 12 or 13% for the month. But there is also a non-zero chance that both VGC and NPD numbers for 360 are high for the month . It should come as no surprise that HW sales numbers have a margin for error. Both NPD and VGC get hard data form certain sources, and then they both have to estimate and extrapolate to arrive at a final sales figure. It would be a mistake, I believe, to assume that NPD data is always more accurate than VGC data.

Personally I don't think VGC should simply adopt the NPD numbers in preference to their own. To do so would imply a lack of credibility in VGCs own data gathering and estimation methods. I do think the NPD numbers need to be given due consideration, though. Hence my views about what adjustments could be made to the VGC numbers. An upward adjustment for 360 across the entire month of about 70K or 8.7% is what I thought would be a reasonable consideration of the NPD data (i.e. I do not think VGC number crunchers should actually accept that they undertracked 360 numbers by 100+K). And yes, I think an 8.7% upward adjustment is modest. You might think it's a major adjustment, that's fine we have a different view about what's major and what's modest. But in the imprecise world of trying to pin down console sales numbers 8.7% isn't really that much.

It's only in this case where 8.7% (or more if you really want to insist on that full 100K adjustment) means the difference between coming 2nd and coming 3rd that it's got people all excited. If 360 and PS3 were both about the same between VGC and NPD and it was Wii that had the possibly statistically significant differential no one would say much at all. Why? Because Wii would go from being well out in front to being slightly more well out in front; no big deal. In fact I'd go so far as to say that people would generally conclude that VGC and NPD were well correlated for the month if that were the case.