As just about every statistics student can attest, Simpson's Paradox — a statistical phenomenon where an apparent trend is reversed when you look at subgroups — is notoriously hard to explain. You can look at examples — say, the fact that US wages are rising overall, but dropping within every educational group — but that don't really help to explain the paradox. But it's not really paradox at all, but simply the fact that the disparate rate at which members of the study join the subgroups isn't accounted for in the analysis. To demonstrate this effect, the Visualizing Urban Data...
The burgeoning interest in R demonstrates that there’s demand for analytics to solve real, business-critical problems in a broad spectrum of companies and roles, and that some of the incumbent analytics offerings, in particular SAS and SPSS, don’t sufficiently meet the growing need for analytics in many major companies. Annotated link http://www.diigo.com/bookmark/http%3A%2F%2Fspotfire.tibco.com%2Fcommunity%2Fblogs%2Fenterpriseanalytics%2Farchive%2F2009%2F01%2F08%2Fanalytics-in-the-nyt.aspx
R. Westerholt, M. Gröbe, A. Zipf, and D. Burghardt. 10th International Conference on Geographic Information Science (GIScience 2018), volume 114 of Leibniz International Proceedings in Informatics (LIPIcs), page 63:1--63:7. Dagstuhl, Germany, Schloss Dagstuhl--Leibniz-Zentrum fuer Informatik, (2018)