Trouble With Numbers

I once made myself a little unpopular with my statistics teacher with the Mark Twain quote: “There are lies, damned lies, and statistics.” Numbers don’t lie, but people sometimes lie about what the numbers are telling us.

Consider the possibility that the trouble with numbers often isn’t intentional dishonesty, but misrepresentation committed in good faith or through ignorance or misinterpretation.

The other day I was listening to a podcast where the speaker mistakenly used two statements interchangeably:

  1. Nearly 80% of people between 25 and 40 years old have tattoos.
  2. Nearly 80% of people with tattoos are between 25 and 40 years old.

If a person isn’t paying attention, these sound the same and it’s easy to see how a person could mistake them for the same thing, yet the statements are radically different.

Another example of this same type of error would be saying:

  1. 70% of all men make $300,000 a year.
  2. 70% of those who make $300,000 a year are men.

I made up those numbers to help highlight how two very similar sounding statements can be very, very different.

Or consider the difference between:

  1. 90% of new hires at this company are unhappy.
  2. 90% of the unhappy people at this company are new hires.

Statement #2 doesn’t mean almost all new hires are unhappy, just that of the unhappy people most are new hires. If you have 100 new hires the first statement suggests 90 are unhappy. But if statement #2 is the true one and you only have 10 people in the company who are unhappy, well then 9 of them are new hires. Those are very different situations, requiring different responses.

Be careful out there.

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