During the writing of my post on crossplay, I encountered a problem. When I was looking at the difference in crossplay between the young and the old group, I wanted a way to talk about whether a particular increase for a race or class was more or less than the average increase. I've included a small sample of one of those tables below.
|Crossplay by age for race|
My next instinct was to try ratios (division) for the last column. This would give the humans a result of 1.33, a ~33% increase, and the trolls a result of 1.56, a ~56% increase. While this looks good for these two numbers, I actually have conceptual problems with this as well. Suppose I included a third race here for which the young group had 90% female characters and 100% female characters for the older group. This would give us a result of 1.11 (repeating, of course). I feel that's too low though; going from having 10% male characters to zero is a pretty significant thing. So I wanted something that will scale well at the low end and at the high end. Just as gaining 10 percentage points is a big deal when you have very little, such as the trolls, it's also a big deal when there's not much left to pick from, such as for this hypothetical race.
where p is the percentage of female characters for that group. When I did all the calculations and thought about how I felt about the results, everything just looked right. The values that I felt should be bigger than others were all that way.
So if you're wondering how this stuff get's done; that's how. It's trial, error, and intuition.