Tuesday, August 28, 2012

5 Easy Pieces

Simply Statistics put up this link to an interview with David Spiegelhalter on 5 good books to help understand statistics and risk.  I haven't read any of them, but they looked excellent.  Also, this quote is excellent:
There is a nice quote from Joel Best that “all statistics are social products, the results of people’s efforts”. He says you should always ask, “Why was this statistic created?” Certainly statistics are constructed from things that people have chosen to measure and define, and the numbers that come out of those studies often take on a life of their own.

I'm pretty sure that about sums it up.

Monday, August 27, 2012

Skin cancer, sunscreen, and connecting the dots

There is skin cancer in my family.  My grandfather has had it, and occasionally a doctor will try to tell me that I am genetically predisposed to it because of this.  While I try to practice good sun habits, I am dubious about the "genetic predisposition" argument.  You see, my grandfather spent several years in the early 40's hanging out in the sun in the Phillipines while monitoring Japanese aircraft activity.  He thinks that's more responsible for his skin cancer than genes.  I do too.

Regardless, you might say, it's a good idea to wear sunscreen right?  Of course.  Except it may not help.

As it turns out, sunscreen formulas that prevent sunburn may not be equally good at preventing cancer.  And you may not be putting enough on.  And they may have chemicals in them that actually increase your cancer risk rather than decrease it.  Huh.

I've talked before about making sure you connect all the dots, not just proving disjointed ideas.  We know that sunscreen prevents sunburn, and people who get sunburns are more likely to get skin cancer.  The troubling part is that there is no proof that people who wear sunscreen get less skin cancer.  It's tempting to jump from A to C, but you have to remember things can go wonky when you don't remember the stop at B.

Regardless of the data, sunburns are painful, and I'm still very Irish, so I would recommend sunscreen in general...but lets not oversell the good it might be doing.

Sunday, August 26, 2012

Religion and income

Religion and income distribution.  Not sure I get exactly what data they used to get this, but still kind of interesting.  Incomes seem to skew upward the smaller the group, which makes a certain amount of sense.
 The Hindu numbers surprised me a bit.  I was guessing that has something to do with the high percentage of Indians in tech/healthcare professions, presumably making $100k+.  

Things to ponder on a Sunday

Thursday, August 23, 2012

Retractions, while sometimes necessary, are never as good as the real thing

Since starting this blog, I've become quite the fan of the website Retraction Watch.

One of the more interesting ongoing stories has been the number of retractions from Dipak Das, the UCONN researcher who faces massive misconduct charges for fabricating data in his research about the health benefits of red wine.

His current retraction count stands at 13 papers, with 145 counts of misconduct being investigated.

While the role of his work in the field is contested, one can't debate that his results were widely reported and certainly helped with the public perception that red wine is good for you.  Thus, I found it interesting that Jezebel was running an article at the same time about the further proof that red wine is good for you.  In the background they mention some of the studies that Das did, that have since been retracted.  Not that this is necessarily their fault....recently it was found that only a quarter of retracted articles in online databases carry a retraction notice, and this drops to 5% if you look at downloadable PDFs.

People have complained about this with newspapers for years....large headlines, little tiny retractions...but with the ever increasing retraction rate and the centrality of the internet, this is liable to get worse before it gets better.

Tuesday, August 21, 2012

Economic Data, and why I don't talk about it

I find it really hard to even comment on economic data on this blog.  It's based on so many assumptions and there are so many different numbers that can be included or excluded that critiquing it is a combination of trying to shoot fish in a barrel and trying to catch a greased pig.

Not my idea of a good time.

Anyway, BD Keller linked to an excellent post today that is way more articulate than I about why evidence based monetary policy is so hard to come by.

On economic experimental models:
Think of a good experimental design: randomised control variables, holding everything else constant, etc. Now think of the worst possible experimental design. Imagine something that engineers or psychologists might dream up over beers for a laugh, or to illustrate what not to do. That's what economists face. It's as if our lab assistants (the fiscal and monetary authorities) were deliberately trying to make our (economists') lives as hard as possible. They do this, of course, not to spite us, but to try to make everyone else's lives as easy as possible. To get a good experimental design for economists, both the fiscal and monetary authorities would need to be malevolent.
Makes sense, but given this, I do wish they'd stop saying their predictions with such authority.

Sunday, August 19, 2012

Does egg = cigarette?

Oh CNN, your headlines make me sad sometimes.

Is eating egg yolks as bad as smoking?

No.  No it is not.  The study you're reporting on does in fact claim that eating egg yolks accelerate heart disease about 2/3rds as much as smoking does, but acceleration of heart disease is not actually the health problem smoking is most known for.  But you know that.  Sigh.

Not that I'm buying the study anyway.  They asked people, who already had heart disease, to report their egg yolk consumption over the course of their lives.  How accurately can you recall your average egg yolk consumption over the course of your life?  Additionally, people who have heart disease have most likely been told to cut down on consumption of saturated fat and cholesterol.  Those still eating more eggs have likely heard this advice, and disregarded it.  What are the chances that they're disregarding other advice as well?  Lastly, it does not appear the study asked about the consumption of any other food, meaning egg consumption could actually just be co-occuring with the consumption of something else that was even worse.  Surveys that ask only about very specific foods tend to see what they want to see.

So basically, another correlation/causation issue here, combined with those terrible consumption recollection surveys, with a sprinkle obnoxious headline writing.   Yeehaw.

Saturday, August 18, 2012

Now THAT's how you write a science headline

"Babies Shun Altruism, Prefer Bouncing"

Speaking of replication of results, this study failed to substantiate the idea that 10 month old babies had a moral code.  Turns out that the their preference for "helpful" robots was based less on the fact that the robots were helpful, and more on the fact that they bounced.

I'm sort of curious how many of the original study authors were parents.  I've only been a mom for 19 days and even I could tell you that babies like bouncy things more than discussions about man's existential angst.  The 2 AM feeding helps you figure these things out pretty quickly.

For fun, I decided to conduct my own n=1 experiment and to present my son with a survey regarding his preference for robots in general and their morals in particular.  I thought it was a fairly well crafted survey.

I think my findings are best summarized with this picture:
I think that should be good enough for any number of social psychology journals.  

Replication of results

I haven't talked much here about reproducing results of studies, mostly because most studies have so much to pick at from the outset that it doesn't matter.  However, a new initiative is looking to highlight reproducibility in scientific studies, and encourage independent verification of results.

I think this is pretty cool.

Right now, journals tends to value originality of research over anything else, and that can lead to incentive problems.  In fact, the woman who helped start the replication initiative did so after she had trouble finding someone to publish a paper that called in to question her own previous research when she was unable to replicate it.

Repeating results is supposed to be one of the fundamentals of the scientific method.  Good to see it finally getting it's due.

Wednesday, August 15, 2012

Year of the Snake (also, Statistics...but not Algebra)

My credit for links is beginning to go downhill, I blame the baby thing.  When I find good links, I leave the page open in Chrome, but don't often leave the source open as well.  No one told me having a child would cause my internet etiquette to go so precipitously downhill.

All that to say, I have no idea where I saw this, but apparently 2013 has been declared The International Year of Statistics.  

Sadly, none of the events are in my neck of the woods, but still fun to know about.  

It also brought to mind this NYT Op-Ed piece about the necessity of algebra.  I'm a bit tardy in bringing it up, as there have been quite a few good responses to it already, but I wanted to throw my two cents in.  

Andrew Hacker argues that algebra and other current math standards are impractical and unfairly hold back people who aren't good at math.  My first reaction was annoyance.  No one would ever argue that someone deserved to graduate high school without being able to read, no matter how much they excelled at math....and yet here someone is essentially arguing the reverse.  

When I took a deep breath however, it occurred to me that the last thing I want to do is defend the way math is taught to most high schoolers.  For many people, a course on functional statistics and/or financial math would be more useful, practical, and most likely easier to learn and remember.  If we're headed that direction, there's probably very few subjects taught in high school that couldn't be improved with a little more practicality and a little less theory. 

To get back to the start of the post, I wouldn't mind seeing algebra replaced with more statistical teaching....though large scale public understanding of stats and research methods might leave me with fewer things to blog about.  

Monday, August 13, 2012

Olympics of Yesteryear

Well the Olympics have come and gone, but I'm still not over my crush on the plethora of Olympic related data out there.  Indulge me one last time, as I repost the Economist's list of discontinued Olympic events.

Who knew tug of war was in there until 1920?  They should bring that back.

Sunday, August 12, 2012

Anti-conservative bias and social psychology

My most popular blog post of all time was the one I did on conservative trust in the scientific community vs retraction rates.   I called it "Paranoia is just good sense if people really are out to get you" because I had a suspicion (confirmed when I ran the data) that conservatives might actually be behaving rationally when they said they trusted science less, given the ever increasing retraction rates in prominent journals.

Now, a new study shows that this distrust of the scientific community is even more well founded than I originally thought.

In a survey conducted by two self proclaimed liberals, it was found that there is heavy evidence that conservatives are being systematically discriminated against in the field of social psychology.  What unnerved the authors even more is that this was not a case where people were hiding their bias:

To some on the right, such findings are hardly surprising. But to the authors, who expected to find lopsided political leanings, but not bias, the results were not what they expected.
"The questions were pretty blatant. We didn't expect people would give those answers," said Yoel Inbar, a co-author, who is a visiting assistant professor at the Wharton School of the University of Pennsylvania, and an assistant professor of social psychology at Tilburg University, in the Netherlands.
He said that the findings should concern academics. Of the bias he and a co-author found, he said, "I don't think it's O.K."

The study isn't available yet, so I can't say I've read the nuances.  Still, it's hard for me to believe two liberal authors would have attempted to skew the results in this direction.  Conservatives have claimed this bias exists for years (look no further than the ethics complaint lodged against Mark Regnerus for proof), and will no doubt find nothing shocking about the results.  For liberals to have to face what this means however, that's something new.  Even in the comments on this article, the vitriol is surprising, with many saying that conservatives are so out of touch that it is an ethical responsibility to keep them out of fields like social psychology.


It is much to my chagrin that social science gets lumped in with harder science, but since findings in this field are so often reported in the media, it makes sense to take them in to account.  We have a vicious cycle here now where some fields are dominated by one party, who then do studies that slam the other party, then accuse that party of being anti-science when they don't agree with the results.  This is crazy.  The worst thing that can happen to any scientific research is too much consensus....especially when it involves moving targets like social psychology.  With 40% of the population identifying as conservative, how can we leave those perspectives out?  Everyone, liberal and conservative, should be troubled by these findings.  Those untroubled by this should take a good look at themselves and truly ask the question "what am I so afraid of?".

Tuesday, August 7, 2012

Olympic visuals

One of the nice parts of having a baby during the Olympics is that there's always something interesting on TV at 3am.

I had posted a visual representation of the winners of past years vs the winners today last week, and yesterday I saw an even better one.   It won't embed, but it's worth a watch.  It focuses primarily on Usian Bolt's 100m dash time.  Apparently the gold medalist from 1896 still would have had 65 feet left to run when Bolt finished.

Additionally, the bronze medalist from 1896 would be finishing on par with today's record setting 8 year olds.  It's interesting stuff, even if (like the AVI) you believe there's chicanery involved.

Monday, August 6, 2012

Growth charts and tiny babies

This is another post that reflects my current life situation, but it highlighted some pretty interesting issues with data tables.

This issue is particularly interesting to me because I delivered via unplanned/urgent c-section, in part because of some abnormal measurements found during a routine ultrasound.  We had to have quite a few follow up consults and testing (among other things, they actually had to assess for achondroplasia - better known as the major cause of dwarfism)*.

Given this, my mother thought I'd find this Wall Street Journal article on baby growth charts interesting.  Essentially, baby growth charts were set several decades ago based on a population that's different from what we have now.  The CDC does not want to readjust the charts, as it would make obesity look more normal than they think it should, and this is causing a situation where a high number of children are measuring "off the charts".

It's an interesting situation when you realize that 95th percentile doesn't actually mean "larger than 95% of children of the same age" but rather "larger than 95% of children the same age 40 years ago".

Additionally, it also points out that the CDC growth chart is based largely on formula fed babies, who grow slightly differently from breast fed babies.  So at the same time Mayor Bloomberg is pushing breastfeeding, doctors are potentially telling parents their children need formula to speed their growth up to match a chart that only tracks where they would be if they had done formula to begin with (this is why state mandated health policy drives me nuts so often....you solve one aspect while leaving several causes unadressed).

As the availability of testing goes up, we have to be particularly vigilant to make sure our standards charts keep up as well.  Otherwise we routinize unnecessary testing and freak out new parents.  And from personal experience, I can say that's just not nice.

*It was ruled unlikely, though apparently we can't get a definitive no until he actually starts growing, or not as the case may be.  There's no genetic history of it in my family or the husband's, though we are both on the short side.  In this case, us being short is actually a positive....it means the abnormalities are more likely natural variations.  Our genetic consult doctor was hilariously terrible though....she suggested if we wanted more information about the condition we watch the reality TV show about it (Little People Big World).  Then she said it was unlikely, but maybe we should still watch the show.  She ended it all with a comment about how it was never good when genetics doctors had too much to say, so we should be happy she wasn't talking too much.  I don't think she was very self aware.  

Friday, August 3, 2012

Weekend Moment of Zen 8-4-10

While I'm still recouping/adjusting, I thought a little humor might be in line.  This one comes courtesy of sometimes reader/my uncle in law Deac, who labeled this a golf joke...but I think it tells us something important about engineers:

An engineer, a priest, and a businessman were playing golf and overtook another group of golfers who were hitting the ball in every possible wrong direction. The clumsy group would miss the ball, hit it into the lake, bump into each other, and accidentally thwack each other when they swung.

The businessman got on his iPhone and called the golf course administrator complaining bitterly about the inconvenience, high golf fees, and insisting that such an inconsiderate, inept group of goof-offs shouldn’t be allowed on “his” golf course.

Upon hearing the response, the businessman shut up and hung up quickly. He contritely told the other two group, “Those are blind golfers. They were firefighters, but were responding to a chemical fire. They saved 30 people, but lost their sight from toxic fumes. I feel terrible for what I said. I’m going to have my company pay for their caddies and green fees forever so they can always play golf. They really deserve our respect and help.”

The priest said, “Those poor men! They selflessly lost their sight to help others. I’m going to have a Golfer’s Mass every month and pray for the return of their sight. Our collections will go to those poor golfers’ families.”

Finally, the engineer said, “Why can’t those guys play at night?”

Wednesday, August 1, 2012

Rich Mom Poor Mom

I have a sleeping baby in my lap, so you'll forgive me if I have a one track mind.

Yesterday we met with a nurse who let us know that in Sweden, they have now set minimums for skin to skin contact between mom and babies during hospital stays.  If you don't do the minimum, you pay the hospital bill.  This morning, in my first perusal around the internet in a few days, I see that Mayor Bloomberg is trying to find ways of encouraging new mother's to breastfeed.

A note on research regarding babies and various practices in infancy:  Babies are a lot of work.  I realize I'm preaching to the choir on this, as many of my readers have successfully raised quite a few children, but it's true.  Many of the practices that show lots of benefits for babies (skin to skin contact, breastfeeding, etc) take even more time than the alternatives.  While I believe these things are good for babies on their own, all data collected on these practices will be complicated by the fact that parents who engage in them tend to have more time, resources, and support than those who don't.  Pushing these practices on those who are already particularly stressed may not have as profound an outcome as it did in the study, as the groups went from self selecting to random.

Something to think about for the policy makers.

Sorry, I've been reading over a lot of hospital literature and getting mildly annoyed.  I think that means the pain medication has worn off.  Nurse!