free variable

You should probably be familiar with Minard’s famous graph of Napoleon’s doomed Russian campaign, which Edward Tufte calls “[p]robably the best statistical graphic ever drawn.” Well, a blogger at the OmniGroup site has used the OmniPlan software to present Minard’s data as a Gantt chart. I find the juxtaposition of total military failure and massive loss of human life with the bureaucracy and management-related tedium implied by the Gantt chart to be rather amusing, but I must say — with all due respect to the Omni team — that their image falls rather short of “[p]robably the best statistical graphic ever drawn.”