Chapter 7
Spotting Differences
Sports commentators like to classify a select few athletes as superstars or as part of an elite group, while the rest are designated average or role players. These classifications usually aren’t so much from sports statistics as they are from watching a lot of games. It’s the know-it-when-I-see-it mentality. There’s nothing wrong with this. The commentators (usually) know what they’re talking about and are always considering the context of the numbers. It always makes me happy when a group of sports analysts look at performance metrics, and almost without fail someone will say, “You can’t just look at the numbers. It’s the intangibles that make so and so great.” That’s statistics right there.
Obviously this doesn’t apply to just sports. Maybe you want to find the best restaurants in an area or identify loyal customers. Rather than categorizing units, you could look for someone or something that stands out from the rest. This chapter looks at how to spot groups within a population and across multiple criteria, and spot the outliers using common sense.
