Using Context Clues to Predict 3

[cdude1034]

Sqrl said:

cdude1034 said:

 

	April '07	June '07	Sept ' 07
Wii	1.32 mi/mo	1.23 mi/mo	1.18 mi/mo
PS3	.63 mi/mo	.51 mi/mo	.46 mi/mo
XB360	.57 mi/mo	.53 mi/mo	.50 mi/mo

Looking at theses numbers I find the most interesting thing is that the 360 as of the last three months at least is outselling the PS3 just barely. I’m pretty sure most people would predict the opposite. I did.

 

These numbers aren't very usefull. Not trying to kill your arguments (still haven't read through your thread but I am going to after I write this).

Anyways, launches have high points in sales and so will the holidays, so all of the consoles are clearly going to be coming down right now. Then we have a situation where because the PS3 is closer to its launch/X-mas and also its EU launch (which was sizeable) its average is going to be deceptably high. Same with the Wii to a lesser extent (only reason its a lesser extent is it didn't have a EU launch in spring). The 360 is going to be deceptively low relative to the others because of same thing, only in this case its much farther from its launch.

A good way to use your method of averaging is to instead use weeks over identical periods (to preserve market condition factors) and eliminate outliers. You can determine what you would classify as an outlier but I would suggest setting it in advance rather than deciding when you know which consoles its for etc..., something like 3 standard deviations would do just fine in this situation.

Or you could simply use the Mode of the consoles over those periods.

If your interested I have some basic stats for each console as of current numbers... I will post them and if you want to you can use them. No worries if you don't, I get them from my spreadsheet automatically so its mostly copy/paste.

	Wii	360	PS3
Mean	274,045	116,833	103,161
Median	249,472	88,255	84,102
Standard Deviation	107,886	88,208	81,920
Q1	216,757	76,029.5	64,261
Q3	278,310	111033.5	105,090
IQR	61,553	35,004	40,829

Those are based on weakly WW sales since launch of each console.

 Wow, Sqrl, you have a really good point that I just didn't think about. 

I think a sales per month per quarter would be more accurate. Market conditions do vary a lot during the different quarters, and I'm almost embarrassed to admit that I didn't think about that.

Thanks so much for the insight and I think this was exactly the information I needed to make my next article a lot better. I'm glad to see there are people on this site that can state what they feel or disagree without needless bashing.

Anyway, thanks again, Sqrl.