Sunday, December 2, 2012
This is Not a Normal Distribution
Anthropologie store in Georgetown, DC earlier this year. Ceramic cups are suspended from a shelf by ribbons. The length of the ribbons are generally arranged to produce a bell-shaped curve: shorter ribbons on each end and generally longer ones in the middle. But, no, this is not a normal distribution. The cups are not arranged or ordered by size, volume, weight, or price etc. There is no number line to represent some measurement. The is no frequency distribution showing few small, many average, and few large aspects of the cups. There are different size ribbons, but these do not represent a frequency count of how many instances of some aspect of a cup are accounted for. It does make a nice curving display suggestive only of a bell-shaped curve, but it is not even a rough representation of a normal distribution.