Heteroskedasticity

Heteroskedasticity is a term used to describe a relationship between two variables which has unequal variance over the range. For example, the variance in the length of a cat's tail almost certainly changes (grows) with age. On the other hand, the average amount of chewing gum a person consume probably has a consistent variance over a wide range of human heights.

We also discuss some issues with the visualization shown in the tweet embedded below.

More traffic tickets are issued per person in zip codes with lower average household incomes. [OC] … pic.twitter.com/Xtclzs7Lx8

— /r/DataIsBeautiful (@DataIsBeautiful) August 23, 2016