Statistical Report Flaws: A Spotter's Guide

Statistical reports play an important role in management decisions, so it pays to hone your skills for spotting inaccuracies and distortions. Some flaws are so subtle that even professional statisticians debate their presence, but many errors are easy enough to detect if you just look for them.<br>This article describes some outright errors along with some suspect practices that often lead to error. After examining a few graph-drawing fiascos, the article examines ranking distortions and other problems that can result from either excess precision, ill-chosen scales, or a disconcerting quirk called Simpson's Paradox. Finally, the article discusses a common survey methodology error that leads not only to slanted results but also to the reporting of nonexistent trends.