I have a tendency to jump around from topic to topic in an inconsistant way, and I guess this week/month I'm on a visualizations kick.  I look at a blog called Urban Cartography from time to time as they have interesting infographics and data visualizations posted there.  They had this graphic on it today.   On a side note Urban Cartography doesn't always provide a link to the original, which I think is really silly.  Anyway, this time the graphic had the address written on it and so I was able to read the author's original description.  All this graphic really shows is population density, or urban centres, McDonalds naturally being more accessible where there are more people.  The author notes this in the description.  I think this actually ties in somewhat with the "cartographic malpractice" where Stephen Few discusses the potential misuse of techniques not appropriate to the data.  I don't know if the McDonalds graphic is necessarily a misuse of a technique, all he did is calculate the distance between McDonalds.  This is a fairly simple process using ArcGIS Spatial Analyst, what the author doesn't show (given the lack of a legend) is the color scale.  You could easily reclassify the underlying raster layer to make the McDonalds appear more dense or less dense.  However, the point I want to make is something I've been seeing more and more.  A thing to be aware of when doing any geographic visualization is how the underlying data is going to affect it.  In this case, the obvious factor is population density.  Perhaps a contiguous area cartogram of Mcdonalds per 1000 people (county?) might be more interesting, or just end up showing the same pattern.

This came up in another blog about Mapping Oxford Crime data.  If you scan through the comments, you can see someone also took issue with whether or not the underlying data was accounted for - again the population.  This becomes a general criticism of Web 2.0 and the so-called democritization of the web and crowd sourcing I think.  It is a common criticism that we hear over and over again coming from "experts" - amateurs shouldn't be doing these things (I don't necessarily place myself in either category).  I do lots of things I probably shouldn't - programming for one.  Of course I'm not trying to sell any programs, because no one would buy them.  It is usually pretty obvious when an amateur has created something versus a professional.  This becomes more interesting in the world of the Web 2.0 where how something was created (say by the BBC with the crime map) is generally not divulged.  That's different than peer-reviewed journals where everything is scrutinized to the last detail.  But in journals, the writers aren't interested in telling a story.  The two examples in this entry, though both are using spatial information and geovisulizations to tell a story, are from different sources and purposes.  One is for the amusement of the author, the other is meant to inform a population with the backing of a powerful news organization.  Perhaps, then, the later should be more open with how they created their story...Of course, it is much easier to find faults than to deliver praise.