RSS Feed

Monthly Archives: March 2013

Graphs and False Correlations

Posted on

In February, BuzzFeed posted this article describing teen pregnancy rates in 2008 (which came from a paper from the Guttmacher Institute). The article (it’s really short: go look) has two maps.

The first is from the paper, showing color-coded states according to teen pregnancy rates:

Teen Pregnancy Rates, by State, 2008

Teen Pregnancy Rates, by State, 2008, Guttmacher Institute


The second is a map of states that require contraception education in schools:
States that Teach Contraceptive Use in Sex Ed, 2013

States that Teach Contraceptive Use in Sex Ed, 2013, BuzzFeed


I have a problem with BuzzFeed’s implications from the second map.

BuzzFeed is trying to imply that contraception education is the answer to teenage pregnancy rate increases. Besides the fact that the years of the studies/data are off, the bigger problem is that the maps are not aligned very well to make this correlation true.

According to the paper, the states with highest pregnancy rates in 2008 were NM, MS, TX, NV, AR, and AZ. The lowest were NH, VT, MN, ND, and MA.

According to the contraceptive map, these are the states that require sex ed in classrooms: WA, OR, CA, HI, CO, NM, AL, NC, SC, VA, WV, MD, DE, NJ, RI, VT, ME (and Washington DC). That means that Minnesota, North Dakota, New Hampshire, and Massachusetts don’t have contraception education but have low pregnancy rates, and New Mexico has contraception education, but has the highest pregnancy rate in the country. BuzzFeed wasn’t the only one complaining about the lack of sex ed; the Washington Post also made a quick implication that missing contraception education (and use) might be to blame.

What’s the big deal with posting two maps that may or may not have anything to do with each other? It sets up a false correlation between the two issues, which can be misleading. I have no data, but I’d guess that if kids do see contraception education, they probably have a greater chance of using it (as opposed to never hearing about it). But after skimming the article and its implied ties, some people may have come away with a sense of, “If we only increase sex ed in schools, teen pregnancy rates will go down!”

Okay, so what’s a better correlation? As a teacher, I see a better link between the teen pregnancy rate map and this:

By State Map, SAT and ACT scores combined

By State Map, SAT and ACT scores combined

Education levels. In general, the low-pregnancy rate states have higher test scores than the higher-rate states. This is a lovely map of ACT and SAT scores (deeper blue means higher scores). I think the map looks much more like the original.

But here’s the real issue: I also cherry-picked the map I wanted you to see. Linked to that ACT/SAT map are the individual maps for each test, and I didn’t think they worked as well to prove my point. In other words, you, the reader, are manipulated all the time by statistics and people who claim to know statistics. I could have also used this map:

USA Annual Mean Temperature

USA Annual Mean Temperature, By State Map


This map also works pretty well to my eye, and would seem to indicate that the hotter the mean temperature, the more teen pregnancies you can expect (except for a glaring problem with Nevada, and New York’s not great either).

What to do about it? Know how you’re manipulated through statistics and false connections. This article from Cracked is a decent start. Check out Number One: Correlation does not equal Causation.

Advertisements

Lunch Dates: Mythbusters

Posted on


“The difference between screwing around and science is writing it down afterward.”

This was one of the last lines Adam Savage gave as part of their Behind the Myths touring show.

Having been treated to these tickets and staring at them in my hot little hands for a while, I’ve been dreaming and scheming of what kinds of questions to ask Jamie Hyneman or Adam. I didn’t actually ask any questions during the Q&A portion of the show (so many little kids wanted to ask about favorite explosions and scariest myths!), but I realized that there were a lot of things I’d love to discuss with them.

Tested was also billed as their new all-Adam-and-Jamie website (although I’m not so clear on the “new” designation, since I’ve been using the Reed Nuclear Reactor video for a couple of years, and their forums (fora?) go back three years). Definitely some cool, nerdy stuff going on in there.

I think a lot of people would love to have lunch with the Mythbusters. Why are so many people so fascinated with them? I think it’s safe to say that there are only a few kinds of people who watch Mythbusters: people who like explosions, kids who like explosions, people genuinely interested in why things work (or don’t work), and a few teachers. Those interested in explosions would have been far less interested in the early seasons. I’m certainly not one to complain about explosive myths, but there are a lot of myths that don’t involve C-4.

To me, Mythbusters is a lot of what I like in everyday people: curiosity about anything and everything, a go-for-it kind of infectious enthusiasm, and (at least to an outsider) fantastic reputations on a personal level. Jamie and Adam seem like genuinely good people, who work on things they like and want to try things for other people (and do some cool things along the way). And apparently, Adam likes to cook, which is definitely a plus in my nerdy-cooking family.

Questions to ask during lunch:

  • Are there criteria for types of myths that make the show?
  • What kinds of footage don’t make it to the TV show that you wish viewers would see? (Does it depend on the myth?)
  • Is there a myth you’d like to test, but it would be too boring for TV?
  • Who have you met, famous or not, who impressed you as a fan?
  • Do you consider yourselves professionals or hobbists?
  • To you, what’s the difference between a good use of tech and a poor or gratuitous one?
  • Adam, do your kids go to public or private school?
  • What are most U.S. kids missing today as part of their (formal or informal) education?
  • Do you like the idea of gadgets and technology in the classroom? What kinds of problems do you think tech solves?
  • Do you think STEM education is the right way to go for U.S. public schools?
  • Do you know of Gever Tulley? What do you think of him?
  • Would you like an official education person on staff at Mythbusters? I might know someone with an interest…

Online Education FTW?

Posted on

This morning I tore off the top sheet on my one-a-day-calendar (the F in Exams version) and found the following:

Quite frankly, teachers are the only profession that teach our children. — Dan Quayle, politician

While sadly Quayle-ish, it’s also a true statement in terms of most formal education. It’s easily arguable that kids (and everyone else) learn constantly from various experiences, good and bad, happenstance and designed. But for the most part, and especially for a lot of kids in public education, their designated learning time is during Monday through Friday, from about 7 or 8am until 2 or 3pm, from August or September through May or June, and that’s all. And isn’t it strange that kids are told “You! go learn! Now!” There’s also a sort of tacit implication that weekends and vacations are non-learning (anti-learning?) times.

Then came this little gem, a quick blog entry about why online ed doesn’t get much credit from teachers. (By the way, MOOC means Massive Open Online Course, and I think VLRC means Virtual Learning Resource Center.) While the author, Amy Bruckman, is a professor at Georgia Tech, and therefore is coming from a post-secondary education view, I think this piece is still very true for secondary education.

There are a lot of proposed changes to the public education system in the U.S.. Suggestions include charter schools, open classrooms, more standards and testing, online-only courses, Kahn Academy, online degree programs, the Teach For America programs, and so on. All of these possibilities are touted as game changers, new ways of thinking, new ways of teaching. Few of them have actual data to show benefit to students. And, like Bruckman says, few, if any, of these ideas, come from the collective educational departments across the country. Is it some grand conspiracy by teachers to keep their stagnant, terrible, downward-spiraling jobs and suppress education reform, or is it more that teachers and school districts want to see some proven data before subjecting the kids they care about to new systems?

Here’s the core of the matter: It’s not about getting rid of the old ways (it’s hard to find data that say the old ways actually don’t work — they do work for a majority of students or else we wouldn’t be using them). New education systems can be fantastic resources and should be promoted and used as such. Many of these new systems and ideas are brought up as an “us verses them” scenario: only one way is the correct way and will actually make test scores increase, and the new and old methods are mutually exclusive. It’s pretty sad to think that teachers would outright reject a new idea just because it’s new. I believe good teachers do try to integrate some new things because they’re new and exciting and have possibility and sparked an interest in them so it might ignite something in their students.

But there’s more to this rapid influx of new methods, and it’s more insidious. There are so many new ways (almost fads, in the way they appear and disappear) that say the current system is broken, some people (even politicians) think that our teachers are broken or incompetent or lazy. Society needs to recognize the amount of work that goes into preparing a body of knowledge for 180+ students’ consumption on a daily basis, and attempting to make it enthralling. It’s about recognizing that teachers do give some genuine input and value in the classroom and in the education of students. Some people can learn in a vacuum or room only populated by computers, but not many can learn the nuances of a subject without others’ experience, encouragement, and constructive criticism. My favorite teachers taught me something about how to be a good person, and not just about geography or English. That kind of education could never come from pixels.

It’s about respect for people in the professional field of teaching.

Levels of Fandom

Posted on

This is what a fan does…. or is it too much?

Lunch Dates: CGP Grey

Posted on

Starting with “Hello, Internet”, CGP Grey has produced a whole bunch of quick and informative videos on topics ranging from animal misconceptions to electing a new pope to the non-planet-ness of Pluto (one of my current favorites for physics classes). This makes his YouTube channel hard to classify (oh darn!), but that much more interesting to the general user (as opposed to a dedicated science or history blog, for example).

Despite the stick-figure-with-glasses persona, there’s a bit more to him than black digital lines. An American living in London, Colin Grey has degrees in physics, sociology, and science education… just my kind of guy.

With a fast-moving pace and equally-fast wit (tossing in a little sarcasm and irreverence), Grey keeps his viewers moving along some good questions. His conversational style keeps my students (and me) enthralled in his topic of choice.

I appreciate that Grey actually researches (and/or lets other people research) his topics and even cites his references at the end of his videos. It makes my little teacher-nerd heart go all wibbly. Hooray for quality over quantity, and with citations!

A lot of questions I’d like to ask him were actually asked in his recent video,
Q&A With Grey for 500,000 Subscribers, however, here are some other things I’d like to think I’d ask during lunch:

  • Why did you start making videos?
  • With your education degree, did you ever teach in a UK classroom? (if yes, what did you teach?)
  • Are you hiding your face for a reason? a giant facial scar or a secret bloggy rant opportunity?
  • I know there’s a store for CGP Grey merchandise, but what else did you (do you) want to get out of the videos?
  • How are the American and UK educational systems similar? different? (in good ways and bad and indifferent)
  • Why would you like to see computer programming instead of foreign language? some programmers argue programming IS a foreign language.
  • What kinds of researching skills do students need today?
  • What sciences should students take in secondary education? to what degree?
  • Should secondary education be compulsory?
  • What do you think about cursive coming back into elementary-level curricula?
  • What’s a good way of evaluating whether your videos do a good job of conveying their intended purpose?