Seems I'll have to improve the analysis then. :)

I understand what you are saying, and I will readily agree that this IS a problem, for now. I don't think it's invalidating the entire analysis (or I wouldn't have made it), I still think the basis is very sound, but I can see why you have problems accepting something with such big holes in it.

That's totally going to be a pain in the butt. If there's anything I DO NOT want to do it's to dig up every single weekly data, but on the other hand... maybe I won't have to. I could do it based on 13 week averages. I'll include that in the next one, shouldn't be all that painful.

Thanks for the input.

When I started doing this I was completely unambitious. All I was thinking was to do some rudimentary tracking of adjustments. I really had no idea how to go about it or what I would do with the figures. Eventually, the idea that it could be used as a token measure of VGChartz weekly accuracy crept up. I've struggled to make it a somewhat accurate analysis based on the numbers I have collected.

The "absolute adjustments" thing is one of the things I then felt was necessary in order to show how big the adjustments are in a normal week. They aren't really all that great as a measure of accuracy however, because of the things you mentioned. The cumulative adjustments are necessary to keep track of which consoles are being overtracked and which are being undertracked, which is a huge deal for fanboys all over the internetz when bashing this site.

I'm also going to add a "Original weekly figures" row, and how much that differs from the now adjusted figures, so that cumulative adjustments made on the weeks I have tracked will be readily apparent.

What I'm trying to do here is give a feel for what's ACTUALLY going on behind the scenes. There are so many rumours and misconceptions about adjustments it's insane. I'm trying to show how big the adjustments are every week and put that in some sort of context, so that people like Mike_B doesn't have to go unanswered when saying that VGChartz is completely inaccurate and not trustworthy.

Thus what weeks the data is coming from is less important to me than how big the adjustments are. I'm not 100% about this, but I have a feeling that apart from last years insane Christmas weeks these 12 weeks have been pretty standard when it comes to adjustments.

I just did that!

And thanks. I completely understand why you are not doing this yourself. It would take an insane amount of time to keep track of all individual adjustments. I shudder just thinking about it.