Poor Justin Gatlin. The guy sprints to a world record 100 meters then sees his record taken away due to rounding. His 9.766 time got rounded up to 9.77 -- leaving him tied with Asafa Powell. You might think hundredths of a second offers enough precision to distinguish winners from losers. As sprinters cross the finish line they’re traveling about 15 centimeters each hundreth of a second. Does recording 100 meter times in hundreths of a second provide enough detail to record the desired outcome: determining who is the fastest man in the world?
In Justin’s case, he was running a race that was measured with insufficient precision. He may be the world’s fastest man by a few inches--enough that an attentive spectator would notice.
In business, however, we often err in the opposite direction. We measure and argue about precise numbers when directional accuracy is all that’s needed. If I were to run a race against Justin Gatlin, a sundial would provide enough detail to show the faster runner.
Ask yourself, how much precision do you need? In the case of Zillow, the online home valuation database, too much precision can be a problem. It can mislead users to think the precise numbers are also accurate. Precision has costs. Not always in money, but often in attention. Have you found yourself derailed in a presentation because the Marketing’s numbers don’t exactly square with the numbers from Operations? Does it matter? Probably not.