statistics
mikethemadbiologist | May 2, 2010Clive Thompson nails it when he describes the importance of statistical thinking (italics original; boldtype mine):
Statistics is hard. But that's not just an issue of individual understanding; it's also becoming one of the nation's biggest political problems. We live in a world where the thorniest policy issues increasingly boil down to arguments over what the data mean. If you don't understand statistics, you don't know what's going on -- and you can't tell when you're being lied to. Statistics should now be a core part of general education. You shouldn't finish high school without…
mikethemadbiologist | April 5, 2010Republicans are in a bit of a bind regarding the U.S. Census. In the past, they have opposed "statistical sampling", which would readjust the Census results to account for undersampled groups, such as the poor and minorities, which typically vote Democratic. In fact, congressional Republicans made Obama's Census director pinky-swear not to do this, and he did:
Robert Groves, director of the University of Michigan's Survey Research Center and a former Census Bureau official, is an expert on statistical sampling, the practice of extrapolating a larger population from a smaller slice of it.…
stoat | March 21, 2010 Actually this is a post about statistics, but what the hell I've been listening to Carmina Burana a lot recently, even if Miriam thinks it is bombastic. So anyway, several people have commented on this article which (whilst it makes some points about statistics that are vaguely plausible) far far overgeneralises its bounds of validity: any single scientific study alone is quite likely to be incorrect, thanks largely to the fact that the standard statistical system for drawing conclusions is, in essence, illogical. Tamino points out the obvious: that statistics works, and it isn't stats…
mikethemadbiologist | March 18, 2010After finding this post about income inequality and social problems, I decided to check out the 'book version', The Spirit Level: Why More Equal Societies Almost Always do Better, by epidemiologists Richard Wilkinson and Kate Pickett. It has a lot to recommend it (if you want the short pdf version, it's available here). First, the evidence for a correlation across countries and within countries between income inequality and social misery is pretty overwhelming. Second, in the introduction, as opposed to an appendix nobody will read, Wilkinson and Pickett explain the basics of the…
mikethemadbiologist | March 15, 2010Friday, The NY Times reported on Greece's ongoing financial troubles. There is something to be said for discussing whether pensions should begin at age 50--it touches on economics, social values, and so on. But then the reporter refers to some 'analysis' by the Cato Institute:
According to research by Jagadeesh Gokhale, an economist at the Cato Institute in Washington, bringing Greece's pension obligations onto its balance sheet would show that the government's debt is in reality equal to 875 percent of its gross domestic product, which is the broadest measure of a nation's economic output…
rallain | February 7, 2010Looks like the show Sport Science (on ESPN) might take the place of Fetch! With Ruff Ruffman as the target of my bad-science attacks. Note: it looks like ESPN has the short episode I will be attacking online, so check it out.
Let me start off with the big problem (which The Onion already talked about). Why do you want to make a show about science that has really terrible science (if you can even call it science)? I really don't get that. If you want to just talk about cool sports stuff, do that. Please don't call it science. Ok. Now on to the particular attack.
In the last episode,…
revere | January 26, 2010[Previous installments: here, here, here, here, here, here]
Last installment was the first examination of what "randomized" means in a randomized controlled trial (RCT). We finish up here by calling attention to what randomization does and doesn't do and under what circumstances. The notion of probability here is the conventional frequentist one, since that's how most RCTs are interpreted by users. Before we launch into the details, let's stop for a minute to see where we've been and why.
We began with a challenge to you, our readers. In the first post of this series we described an…
revere | January 16, 2010[Previous installments: here, here, here, here, here]
After a detour through the meaning of causation and the need to find a substitute for what can't, in principle, be observed (the counterfactual), we are now ready to consider what many of you might have thought would be the starting point, randomization. It's a surprisingly difficult topic and this post will probably be more challenging for non statisticians, but I feel confident you don't need to be an expert to understand it.
First a quick recap. If you want to know if mammography screening will prolong the life of a woman under the age…
revere | January 5, 2010Just a day into the New Year I was feeling feisty and issued a challenge to readers and the Evidence Based Medicine (EBM) blogosphere in general. I asked for a critique of a fictitious uncontrolled, non-randomized non-blinded small scale clinical study. It was truly a fictitious study. I made it up. But I had a template in mind and I intended to go somewhere with the example and I still do. But it will take longer to get there than I anticipated because it has raised a lot of things worth thinking and talking about in the meantime. I was going to wait a week to give people a chance to read…
revere | December 6, 2009Like David Rind over at Evidence in Medicine I'm a consumer of statistics, not a statistician. However as an epidemiologist my viewpoint is sometimes a bit different from a clinician's. As a pragmatic consumer, Rind resists being pegged as a frequentist or a Bayesian or any other dogmatic statistical school, which is wise. Let the record show most practicing statisticians are similarly pragmatic, as was the great R. A. Fisher, who thought there was a place for different viewpoints in different contexts, even though Fisher was famous for his argumentative and contentious manner (people are…
revere | December 4, 2009Marilyn Mann pointed me to an interesting post by David Rind over at Evidence in Medicine (thanks!). It's a follow-on to an earlier post of his about the importance of plausibility in interpreting medical literature, a subject that deserves a post of its own. In fact the piece at issue, "HIV Vaccines, p values, and Proof," raises lots of interesting questions about different ways to view what we mean by probability (the nub of the frequentist/Bayesian debate), the difference between proof and evidence, the thorny and mental cramp produced by the question of multiple comparisons, and finally…
grrlscientist | November 30, 2009tags: education, academic achievement, university, college, Crossing the Finish Line: Completing College at America's Public Universities, William G. Bowen, Matthew M. Chingos, Michael S. McPherson, book review
The second book review I've ever published in Nature Magazine appeared last week, roughly the same time I was on a trans-Atlantic flight from NYC to Frankfurt, Germany. Due to my lack of wireless and jet lag, I've neglected to mention this until now. This review discusses a book that I think is very important for everyone involved in higher education to read and think about: Crossing…
razib | November 29, 2009I've been crunching some county-by-county data at one of my other weblogs:
Where the fat folks liveDiabetes and obesityThe white vote for Obama, by county & correlatesAre over-leveraged counties seeing an increase in food stamp usage?
revere | November 18, 2009I have been away (again) and out of internet contact most of the day, dealing with an unhappy family event. So this post is short but illustrates an important point that comes up frequently in epidemiology: the difference between risks and absolute numbers. The illustration is not medical, but I think sharper because of it:
The right-wing blog Gateway Pundit says Christians are the target of more hate crimes in the U.S. than Muslims:
In the real world... Hate crimes against Muslims have steadily declined since 2001. Today there are more reported hate crimes against Christians in the United…
gregladen | October 31, 2009I spent about 45 minutes yesterday in the local HMO clinic. They had turned the main waiting room into a Pandemic Novel A/H1N1 Swine (nee Mexican) Influenza quarantine area, and I could feel the flu viruses poking at my skin looking for a way in the whole time I was there.
Amanda, who is 8.3 months pregnant, started getting symptoms of the flu two days ago. As a high school teacher in a school being affected in a state being affected (as most are) she is at high risk for this. She was one of the first people around here to get the vaccine, just a couple of days ago, but it takes about 10…
revere | October 30, 2009One frequently hears claims that the current swine flu pandemic has been exaggerated because there are "only" 1000 or so deaths, while seasonal flu is estimated to contribute to tens of thousands of deaths a year. There are two reasons why this is not an apt comparison. We've discussed both here fairly often. The first is that the epidemiology of a pandemic and seasonal flu are very different. Epidemiology studies the patterns of disease in the population and swine flu is hitting -- and killing -- a very different demographic from seasonal flu. Its victims are young and many are vigorous and…
revere | October 19, 2009Monday morning, start of week three of the official flu season (which began October 4). CDC's scientific spokeswoman on the flu, Dr. Anne Schuchat has said we are seeing "unprecedented" flu activity for this time of year, including an unusual toll in the pediatric age group. What does "unprecedented" mean? It's not very specific on what precedents are included, but if we confine ourselves to the three years before this one, we can get a good idea of just how unusual this flu season is. This week CDC unveiled a new graphic for their Emerging Infections Program (EIP) (I liked the old one better…
revere | October 10, 2009When swine flu poked its head above water in the northern hemisphere in April our "normal" flu season was just ending. A surge of swine flu cases during a time when influenza was not usually seen was bewildering and confusing, not to mention alarming. We didn't know what to expect nor were we sure if it would peter out over the summer, as flu usually seems to (we may learn differently in the future as we start to do surveillance over that period) and then come roaring back or just disappear. While it didn't peter out very much, the big question was going to happen when the northern…
mikethemadbiologist | September 24, 2009
ScienceBlogling Drugmonkey has some good info about the new shortened NIH R01 proposal. There are a lot of interesting comments over there, so I suggest you head on over and read the whole thing. What I wonder about is if the shorter format will end up 'compressing' the proposal scores, and consequently, result in more 'ties' that have to be broken by the NIH staff.
Let me explain.
In many ways, proposals are like admissions to highly selective colleges and universities. For every one accepted, there are one to three that would be equally qualified. Sure, some are so obviously qualified…
revere | August 9, 2009The other day we did something we don't like to do when talking about flu, we made a prediction. We predicted a bad swine flu season in the fall in the northern hemisphere. The history of flu epidemiology is that making predictions is dangerous. Flu has the ability to make fools out of anyone, regardless of expertise. One commenter in particular disdained the risk we took as being no risk at all. It was perfectly obvious to him (or "anyone paying attention") that next flu season would be a swine flu horror show. It may well be, and then this commenter will certainly gloat and perhaps have…