One of the shiny new features added to Management Studio for 2008 allows you to plot spatial data for any table that has geography or geometry data in the new spatial types. This comes in pretty handy for doing quick visual inspection of small spatial data sets... and it turns out that my early suspicion was correct.
In retrospect, 15% might be a bit too much potential randomness.
Reed Me : Geocoding semi-imaginary data points
Bonnie noticed that the variation much to wide and sent me back to the drawing board. The state of Washington addresses alone turned into a rectangular noise pattern. Whoops. I'm still learning my way around, but even I know that Lynnwood is *not* east of Redmond. Doh! (Sorry, Weird Al. We feex dat!)
We're going to fiddle with some parameters, but it looks like 0.15% (0.0015) might give us an OK seeming distribution of semi-imaginary addresses around the postal code center without putting Yakima addresses in the Pacific Ocean.
A big thanks to the improvement team for getting this cool tool into SQL Server 2008, especially Ivor, for prodding me to take another look at the AdventureWorks2008 data.