There are liars, dirty rotten liars, and then their are statisticians...  This famous quote is actually pretty insightful.  As a friend of mine at 3M once said, "show me how you will measure me and I will show you how I measure up".  Again, this is very insightful.

Let me introduce to you the "Data Uncertainty Principle".  This principle (named by yours truly) is basic, yet powerful.  "Data collected to be used for a predetermined purpose is unreliable".  Simple...  but what are the implications?

If a corporation decides to measure it's sales performance and use those sales figures to give awards to it's employees, the actual sales figures will become unreliable.  Employees will do what they can to inflate the figures... and they will become very creative in how they do it.  They will force sales to be processed earlier in quarters where they can hit a bonus and delay sales that occur in slow quarters to give themselves a better shot at hitting the next bonus.  This is a powerful and universal concept.

It's hard to believe this is true and I won't try to prove it to you in this article.  I'll only leave you to think about it for awhile...