October 21, 2010
Bad Measurement: This Is The Kind of Chart that Really Pisses Me Off
Don't you just hate it when somebody crows, “Our numbers have doubled in the last four years!” but provides no comparison with any other numbers so you don't know if doubling is good or bad or whatever?
Yeah, so Mac's installed base has about doubled in the last four years. So what? The chart and accompanying text include no information provided about changes in the installed base of any other platforms. Or even about the population of computer users: How has the potential market increased in the last four years? Has, for instance, Apple moved strongly into any new markets during this period?
The text with the chart says:
“At today's big Apple event COO Tim Cook presented the chart below which shows the installed base of the Mac. It's just shy of 50 million right now. He added that the Mac business has been growing faster than the overall PC market for 18 quarters running.”
Which of course does not help much. We are given no idea how much faster the Mac is growing than the PC. Wouldn't have made sense to include the PC market on the chart? In fact, the absence of the PC data makes me suspicious. I’m close to assuming that the Mac grew only .05% faster than the PC, and that feeble difference is exactly why the Mac people don't want to show the numbers side by side.
And, speaking of side by side, is that quote above even comparing like measures? Is the “installed base” for the Mac a comparable measure to “the overall PC market?”
Geeze, charts like this really piss me off. Am I being too picky here?
--Bill Paarlberg, Editor, The Measurement Standard
By the way, Bill Paarlberg has never owned any computer but a Mac. The Measurement Standard is a publication of KDPaine & Partners, a company that delivers custom research to measure brand image, public relationships, and engagement.