I don’t have time for a regular post tonight, ironically because I spent most of my night taking a statistics midterm. I’d make a joke about 95% confidence intervals, but I don’t want to jinx anything.
Wish me luck.
Wednesday Brain Teaser 3-27-13
Two part question:
1. What is the next number in this sequence: 0, 1, 8, 11, 69, 88, 96, 101
2. What is the next number in this sequence: 1, 2, 5, 8, 11, 22
The Power of a Question
I’ve been spending the past few weeks working on a survey for work, and it’s been some interesting work. The survey itself took a few hours to write, the rest of the time has been attempting to reword the questions so that we make sure we’re actually asking what we want to ask without affecting the respondents opinion or leading to any particular answers. We’re trying to get some data no one’s ever gotten before, so we have no motivation to guide the questions anywhere in particular.
I was thinking about this when I saw this story today. Apparently the British Humanist Society is going after the Church of England for putting out a press release that said that 81% of British adults believed in the power of prayer. The BHS is taking issue with this because apparently this data was taken from this survey. The question that so many people answered in the affirmative was not actually “do you believe in the power of prayer?”, but rather “Irrespective of whether you currently pray or not, if you were to pray for something at the moment, what would it be for?’.
Now that seemed like a bit of a stretch, so I looked a little further.
It turns out that one of the options on the survey was “I would never pray for anything”. 15% of people answered that, and 4% answered that they didn’t know. Thus, the accurate statement really would have been “81% of people don’t say they don’t believe in the power of prayer” not “81% of people believe in the power of prayer”.
I thought this was a bit of interesting story because I don’t often see survey question nuances/reporting make the news, the Church of England did in fact twist the results, but the BHS did leave out the fact that there was actually a “I wouldn’t pray” option.
It’s not the question, it’s how you ask it.
Monday Fun Links 3-25-12
Because I didn’t get to it on Friday.
This is a sad way to start the week, apparently some little girl totally had my childhood (hell, adulthood) dream come true.
In other news, are sabermetrics coming to basketball?
This is fun: book covers with more honest titles. Gatsby renamed and shots at Howard Zinn? Gotta check it out.
Relatedly…what Dr Suess books are really about.
If you’re looking for an even shorter read, here are the 140 best Twitter feeds of the year.
Salt over replacement
One of my favorite baseball stats to watch people figure out is the VORP, or value over replacement player. This stat is an interesting one, in that endeavors to calculate not just how good a particular player is in respect to zero, but rather in respect to how much better the team does with the player in question as opposed to a perfectly average player from the same year.
There’s a lot more to it than that, but that’s not the purpose of this post. The purpose of this post is to mention that I would LOVE a similar stat for nutrition research. Terri put up a post about a new salt study (and gave me a very nice shout out…thanks you!), and it got me thinking about nutrition research in general.
The short version of the study is that researchers collected surveys from 50 countries, took a variety of studies about sodium contributions to disease, and created a model that purports to show how many deaths are due to excess consumption of sodium (2.3 million)
You’ll notice I didn’t link to the study. That’s because there is no study, at least not one that’s published. This was actually a conference paper that was presented in New Orleans at a cardiology conference. Now this doesn’t mean there’s anything wrong with it. Many researchers use conferences drum up interest/get early feedback on their research (including me). However, this does mean much of what they did is not yet available, and the peer review process is much less stringent.
That being said, there’s not much to criticize* without the details (except the headlines about it, those are awful), but it did get me thinking about the point of all of this. I don’t know exactly what countries were covered, or what the major sources of sodium in their diets were. It strikes me though, that for at least some of the people in these countries may not have a terrible amount of choice in the high sodium foods they’re eating. If sodium is being used to say, preserve food, or if processed (and shelf stable) foods are a big source of calories, or if salt is being used to make vegetable consumption more palatable, could campaigning to reduce it do some harm?
In nutrition research, we can’t just think about what we shouldn’t be eating, but also why we eat those things. Salad dressing is a decent source of sodium in my diet, but I can guarantee I wouldn’t eat as many veggies if I had to stop using it. Does the benefit of the vegetables outweigh the detriment of the sodium? What is the value over replacement? When the low-fat craze hit, many people replaced fat in their diet with sugar. A few decades later, the general consensus is that this was a bad idea.
The fundamental assumption of a study like this is that you can subtract one part of your diet separate from any other piece. In my opinion, what we really need is a study where you at least explore that people can reduce their sodium without otherwise worsening their diet. This critical piece seems to be missing from many nutritional public health initiatives. It’s important though…every dollar spent on an initiative to reduce sodium doesn’t get spent elsewhere. Proving something in a vacuum has to be followed by research proving it in the real world, otherwise you risk unintended consequences. A little vice can be good for the soul.
*Okay, I’ll take a shot anyway. There’s some question about how much good sodium reduction actually does, and I’m really curious how they controlled for racial differences in response to sodium levels.
March Madness, Data Style…or not
Well my alma mater didn’t make it in to March Madness this year, but we did have a good night last night. I caught a bit of the game, but spent most of the night watching Georgetown get crushed by a team that didn’t even exist before 1997. I normally like underdog stories, but I actually was watching the game with a rabid Georgetown alum…so it was a little awkward.
Anyway, I’ve been pondering the role of data in March Madness predictions this week ever since my husband got home from his March Madness auction earlier this week. Unlike the well known “pick a bracket” set-up, the auction is a fun twist where everyone throws in $50 and then bids on the teams they want. Payouts get progressively larger depending on how far your team(s) get. You can get as many teams as your $50 will buy, but if you want to go all in on one team, you can go throw in more money to go higher than $50 (you can’t have spent anything previously if you want to do this). You do not get any money back if you don’t spend it all. Teams are auctioned off in random order.
This has normally been a pretty friendly competition (it’s through his work), so he was a little surprised to show up to see someone furiously typing on a laptop. He asked the guy what was going on, and he told him he’d devised an algorithm based on Nate Silver’s predictions. He had then assigned a relative dollar amount to each team, and was going to attempt to get bargains. My husband (who of course puts up with me on a regular basis) was pretty sure he was over thinking it.
My husband’s strategy has stayed pretty simple over the years: don’t bid until later in the game, pick up a team you think can go all the way, and don’t leave money on the table. He won the first 3 years they did this, and has at least made his entry fee back every year, so I figure he’s got a pretty good strategy.
He watched his coworker with the laptop, curious which teams he would pick. After watching him get two low-cost-but-unlikely-to-do-much teams, he was wondering how he was going to proceed. Suddenly the guy turned to him and said “hey, we get back the money we don’t spend, right?”. “Um….no.” my husband and his other friend answered. The guy blanched a bit.
To me, this is the problem many people have with data. The best predictions in the world are useless if you forget to learn the rules of the game. A beautiful data set is useless if it doesn’t actually help you solve the problem in front of you, and it’s often worse if it sort of helps. Harder to parse out the uselessness, more tempting to apply a flawed strategy. How much better to always keep in mind some basic common sense.
I had an interesting discussion lately that led me to realize that my true interest, perhaps, is not actually data analysis. A more accurate term for what I like is research methodology….the study of how to capture what you actually want to capture. I love the analysis Nate Silver did, but I’m also impressed with my husband who made 3 key observations about this game:
- People spend more money when everyone else has lots of money.
- It’s hard to pick a winner, but easier to pick a team who will at least go to the Elite 8 and make you your money back.
- Money you don’t spend is already lost.
Three simple ideas anyone could work out, but have somehow still made him money. While we don’t yet know the outcome, my guess is they’ll work out yet again this year.
He has the Jayhawks, in case you’re curious.
Happy Birthday to Me!
Bad Data, Bad! turns one year old today!
In honor of the occassion, please have a cupcake.
The comments and discussions here make my day, thank you all for stopping by!
Wednesday Brain Teaser 3-20-13
What’s so special about the number 2520?
What’s hate got to do with it?
I meant to get around to this sooner, but I was intrigued by the Assistant Village Idiot’s posts from a few weeks ago about the Southern Poverty Law Center and their list of hate groups.
I’ve seen that phrase “hate group” tossed around a bit, and I got curious about the precise meaning. It seems like one of those terms that most people have a gut reaction too, but surely there must be an actual definition somewhere? After all, the Whitehouse.gov petition to get Westboro Baptis Church labeled a hate group has almost 350,000 signatures….surely it must mean something?
Well, as far as I can tell, not really*….or at least not one that carries much action.
While “hate crime” has an extremely specific definition and is of interest to the FBI, the FBI clarifies that they do not prosecute groups, only people. When asked if they track hate groups, the FBI’s website says this:
Does the FBI investigate hate groups in the United States?
The FBI investigates domestic hate groups within guidelines established by the attorney general. Investigations are conducted only when a threat or advocacy of force is made; when the group has the apparent ability to carry out the proclaimed act; and when the act would constitute a potential violation of federal law.
So the US government doesn’t really declare anything a hate group, but it will investigate threats by groups. I’m not really sure what the petition was about then, as it seems to me Westboro Baptist has always managed to stay on the right (if awful) side of the law (unsurprisingly, the leader’s a lawyer). There seems to be some impression that getting declared a hate group would force them to lose their tax exempt status…but that seems unlikely given that there’s no legal definition.
So if the government doesn’t track these things, what about the Southern Poverty Law Center? What standards do they use? From their website:
All hate groups have beliefs or practices that attack or malign an entire class of people, typically for their immutable characteristics.
Hate group activities can include criminal acts, marches, rallies, speeches, meetings, leafleting or publishing. Websites appearing to be merely the work of a single individual, rather than the publication of a group, are not included in this list. Listing here does not imply a group advocates or engages in violence or other criminal activity.
Also interesting was their list of 15 different ideologies that they classify hate groups with: Anti-Gay, Anti-Immigrant, Anti-Muslim, Black Separatist, Christian Identity (an anti-Semitic group), Holocaust Denial, Ku, Klux Klan, Neo-Confederate, Neo-Nazi, Patriot Movement, Racist Music, Racist Skinheads, Radical Traditional Catholicism (rejected by the Vatican), Sovereign Citizens Movement, and White Nationalist.
Interestingly, they actually release their rationale for adding individual groups to their list in their newsletters. For example, what it takes to be considered an anti-gay hate group vs a group that believes being gay is wrong:
Generally, the SPLC’s listings of these groups is based on their propagation of known falsehoods — claims about LGBT people that have been thoroughly discredited by scientific authorities — and repeated, groundless name-calling. Viewing homosexuality as unbiblical does not qualify organizations for listing as hate groups.
Interestingly, it appears Massachusetts has 8 listed hate groups, only 4 of whom I’d heard of. I also kind of had to wonder if any Sovereign Citizens were included on the map, or if they all got listed under their own countries. Sorry, couldn’t resist that one.
*In one of those weird issues that drives me nuts, every source I found that cited the “FBI definition of a hate group” pointed to the same document….one that never once gave the quoted definition. This totally weirds me out when it happens. My guess is it started with the Wikipedia article. ALWAYS READ THE SOURCE DOCUMENTS.
Friends don’t let friends dance and derive
I was going to write a post on the SPLC tonight, but my throat seems to have caught fire and my sinuses appear to be attempting an evacuation….so instead please enjoy this video of math majors dancing:
I can’t even imagine what these kids are gonna do when they get around to convolving.
graph paper diaries 