Math is Hard

04 May 2006

culture math

BarbieSeth Godin, the bald leader of the Purple Cow Group (now playing in Vegas three times nightly) has been talking about averages lately. First, the realization that half the people you may be marketing to are going to be below average. Of course, he means they'll be below the median. He later reminds us of outliers, such as including Bill Gates in any net worth survey.

I think we should also encourage people to not fear math.

Average (or arithmetic mean), as a statistic, is, well, below average. The median is a much better metric. Then you can go hog wild and calculate the standard deviation. Once you know that, you've got a much clearer picture of what your data represents. While a median is better than a mean (an average), knowing the variation between points gives you a feel for how (in)consistent your data is.

Bill Gates, Mother Theresa and a steel-worker walk into a pub...

Their average net worth is around $30 billion.

Their median net worth is likely $60,000.

A-ha, you think you're clever, using the median instead of the average.

Then you figure the standard deviation, give up making any assumptions about this group, and just have a beer with them instead.