Infrequently Asked Questions

Not exactly a stats post. Just a thinkin' about stuff and writin' about stuff post. These are some questions I've either been asked at some point, or that I ask myself every night as I fall asleep, fearful that the darkness has no answers, more fearful that it will speak answers I cannot bear to hear. Think of it as a Frequently Asked Questions post, using a liberal interpretation of the terms "frequently" and "asked."

What the hell does the title of your blog mean?

The name "X-Bar, P-Hat" is anything but phonetically unambiguous. It's properly read "ex bar pee hat," and it's properly written this way:

x̄, p̂

However, HTML is annoying and WYSIWYG is my best friend. So I write it "x-bar, p-hat." 

Yeah, but what does that mean?

X-bar denotes a sample mean, p-hat denotes a sample proportion. They're the concrete measurements you get from your sample, and with any luck they're decently close to the true parameters of the population you want to know about. Sometimes they aren't, though. Life's like that. In stats classes, you wind up using these two terms a lot, and they sound funny. That's why I call my blog x-bar p-hat. 

What about the subtitle?

As the numbers rolled in on the night of Barack Obama's second election and it became clear that he'd win, the folks at Fox News were feeling understandably bummed. It was not their night. In a now-famous exchange, Karl Rove listed off some counties whose results were not yet known and speculated that they might swing Republican, to which an exhausted Megyn Kelly responded, "is this just math you do as a Republican to make yourself feel better, or is this real?" Megyn Kelly and I might disagree on a lot of things, but she seems like she'd be damn fun to hang out with. Megyn Kelly is a cool lady. That's where the subtitle of the blog comes from.

Why math? Math sucks and is hard.

I know, right? Math is hard. But then I did it a bunch and it wasn't as hard as before. Math is sort of like vodka I guess: at first it's awful, but then you get more of it and it slowly seems less awful, and then you just can't get enough of it and you develop a problem and all your friends stop spending time with you.

In seriousness though, I used to hate math. I went to college intending to major in creative writing. My first year, I took one required math class, and a ton of English classes and writing workshops. And I was miserable! I grew to hate everyone in my writing workshops, and I couldn't summon any enthusiasm for at least half the stuff we were reading in my English courses. I wasn't having fun with literature like I had in high school. And the strangest thing occurred to me: the classes I most looked forward to during the week were intro astronomy and intro stats. It was the only time I felt engaged and challenged.

I was a little terrified at first. My journals from that year are full of long, hand-wringy entries about abandoning my dreams. Writing was my dream-- I was intensely, passionately devoted to the idea of becoming a writer. I had this whole life plan where I wrote a bestselling fantasy series and it got super-popular and I was the new JK Rowling and people wrote smutty fanfiction with my characters and everything was wonderful. Should I throw away that future just because the classes weren't as exciting as I'd hoped they would be? If I changed my major to math or science, I'd probably have better job prospects... but would that mean I'd sold out? College is supposed to be the time for reinventing yourself, so maybe a radical reevaluation of my life choices was inevitable. Eventually, with the encouragement of a lot of friends and awesome professors, I did change my major to math.

It felt surprisingly good to tackle something that, for years, I had convinced myself I was incapable of understanding. Solving complex proofs and learning totally new things made me feel powerful in a way that writing about Shakespeare had not. And, well, there's this idea that mathematicians hate it when people say stuff like "oh, you do math? I never understood math. You must be crazy smart." And yes, the prevalence of that sentiment betrays a troubling cultural acceptance of numerical illiteracy, and mathematicians aren't wizards, and we'd all be better off if math lost its weird stigma... but there's a part of me that responds to that statement with, "Yes, actually. Math is hard, and I learned how to math, so that makes me smart. as. fuck."

In short: learning how to do fancy math stuff is the best high ever.

 

But why statistics, specifically? It is definitely the worst kind of math.

 Oh I don't disagree with you there. Statistics is hella tedious, and didn't really take off as a science until we had computers to handle all the intense grunt work involved in wrangling large sets of data. I can't imagine how boring multiple linear regression must have been before the advent of statistics software. And even when you've got computers to take care of the fiddly little bits, you can still conduct tons of vigorous tests only to conclude that you really can't conclude anything from the data you have. A satisfying, clear-cut conclusion is possibly the rarest result in statistics. Instead of working toward a proof, you're working toward, at best, a solid "probably." Statistics lacks elegance.

But that's sort of what I like about it. The world is messy and imperfect, and statistics accepts that messiness for what it is. In his book The Drunkard's Walk: How Randomness Rules Our Lives, Leonard Mlodinow posits that the reason the Romans developed theories of probability while the Greeks disdained its study was that the Greeks were concerned with using mathematics to describe beautiful, unchanging universal truths, whereas the Romans cared for only those branches of mathematics that had immediate practical implications. Statistics, much like my underwear, is ugly and eminently practical.

It also helped me get my job. Can't complain about that.

That GIF had nothing to do with statistics.

Yeah I've got a bunch of these sitting around. Most of them, I've collected with the intention of using them on the blog at some point, but I never found an appropriate occasion. I'm sticking my favorites in this post just 'cuz.

 Do you say GIF with a hard g or a soft g?

Soft g, as per its creator's preference. But then my brother scowls at me and I switch to the hard g until he's out of earshot.

Do you have an Erdős number?

No. But my sister does. I think hers is 3. So if we publish something together, I'll get an Erdős number, possibly a 4. Heeeeeey sis, need anything co-authored?

What is your favorite math joke?

A math professor writes an email to his wife. It reads:

My Dear Wife,

I've decided to pursue an affair with one of my students. Please don't take this personally. It's simple math: you are 54, and she is 18. I'm taking her out tonight. Don't wait up.

Sincerely, Your Husband

The wife replies:


My Dear Husband,

I am sad to learn that you place so little value on our years of marriage, but if that's the case, two can play at this game. Tonight, I will also go out with one of your students, and I believe it is I who should advise you not to wait up. After all, it's simple math: 18 goes into 54 a lot more times than 54 goes into 18.

Sincerely, Your Wife

Have you seen that Spurious Correlations blog?

Yes. It's quite clever, I like it.

You work in music research. So what kind of music do you listen to?
Did you know that's my least-favorite question to answer? Basically, think about the handful of "novelty" songs you have in your collection just because they're funny or weird. Like that song about the fox and what it says. Multiply that by five hundred, and you have my iTunes library.

Oh, plus about 100 hours of Homestuck music. But I've given up trying to explain that to people whose music libraries aren't also mostly Homestuck. I don't listen to real-people music.

Homestuck is for horrible screeching teenagers. Aren't you a little old for that?

As long as I'm younger than Hussie, I'm not too old to be reading Homestuck. And by my calculations, the moment at which I'm no longer younger than Hussie will be never. Check and MATE.

Kirk or Picard?

This is a clearly Picard household. Technically I'm the only member of the household who has an opinion on it, but that still makes this a Picard household. And I think that wraps up all the vital questions.