As I’ve mentioned a few times, Deana is making me do this 30-day writing challenge, because a month of writing prompts makes everything better. Or something.
Today’s prompt is a fun one, though, and I’m sure I’ll beat Deana with this one.
Day Seven: What tattoos do you have, and do they have any meaning?
I have one tattoo, on my left shoulder. I got it two years ago.
It’s the Chi-squared Goodness of Fit test.
I’d talked about getting a tattoo for years, but I was never really sure what to get. Then, after going through several relationship and job-related troubles, I decided it was time to do something permanent, to celebrate coming out the other side.
My sister and I had actually gone out a few months earlier to get tatted up, but, considering it was a holiday (I can’t remember if it was Black Friday or Christmas Eve), the tattoo place was closed.
I was living in an apartment, and I commented to my friend Catherine that everyone at the pool had tattoos, but none of them were interesting. I didn’t want any Chinese characters or tribal designs. Knives and snakes and skulls are all, of course, awesome, but I wanted something unique.
That’s where the Chi-squared Goodness of Fit test comes in.
My degree is in math. My graduate degree is in Operations Research. I used the Chi-squared Goodness of Fit test extensively in my Masters Thesis. Then I switched careers, and sides of my brain, and had to leave Chi-squared behind. It was time to bring it back.
I’m sure I don’t have to tell any of you what the Goodness of Fit test is, but just in case:
In English, you have a whole bunch of data, and you have to figure out whether it has any type of organization. Chi-squared is a way to test for statistical significance. It involves creating categories and testing to see whether the data falls into categories the way you’d expect it to. In other words, does the data you see fit the way you expected?
Since things weren’t always fitting the way I expected in my life, it seemed like a good parallel. Plus, the Chi-squared distribution is a little bit skewed, which also fits me, and it’s only as strong as its degrees of freedom, which was also something I was becoming acquainted with.
She took me for a beer first, thinking that might be necessary to get me to go through with it, but there was no turning back at that point.
I handed the tattoo artist a copy of the Chi-squared Goodness of Fit test. He looked at it and asked me, “What is this? Like the formula for crystal meth or something?”
I told him no, and he looked disappointed. I believe he might have kept the piece of paper, just in case I was lying.
It didn’t take long–much shorter than I’d expected–and it didn’t hurt anywhere near as much as I’d thought it would.
And so I now am the proud owner of perhaps the only statistical significance test tat in existence.
At some point, I’ll pay tribute to the other side of my brain and get an inkwell tattoo on the right shoulder, but I’ll wait until I feel the strong need.
Until then, I think my one and only tattoo is a pretty good fit.