Re-expression

Re-Expression

There are 4 goals that explain what we want to achieve when we re-express data:

1. To make the distribution of a variable more symmetric (histogram pg. 185) 2. To make the spread of several groups more alike, even if their centers are different (boxplot pg. 185) 3. To make the form of a scatterplot more nearly linear, as they are easier to describe (pg. 186) 4. To make the scatter in a scatterplot spread out more evenly rather than following a fan shape

The //Ladder of Powers// orders the effects that the re-expressions have on data. If you go too far along, you are always able to back up. Also, when you take a negative power the direction will change; however, you have the ability to change the sign to return your graph's direction.