Margaret, who was an average sales person, moved from Washington, DC to Richmond, VA, whose market is one fifth the size, during the month of June.  When the annual evaluations of sales performance were done in the month of December, she was listed as the top performer in the Richmond market resulting in the company promoting her to Sales Director.  The next two highest ranked Richmond salespeople had been the consistent leaders for the last several years and outperformed Margaret since she arrived in Richmond.  Her very high sales numbers during the first six months of the year skewed her average, placing her above the rest of the Richmond area.  In this example, if the decision makers had correct information handy, and used it appropriately, would they have promoted Margaret over her new Richmond peers?

Here is another example.