The Worst Statistics is No Statistics

June 26th, 2008

Mark Chu-Carroll likes to say that the worst math is no math. John Cole brings us an example from CNN. I posted a comment on their article, but it’ll probably get bigger exposure here. (Assuming CNN’s moderators approve it at all.) This was the offending quote:

There were 143 gun-related murders in Washington last year, compared with 135 in 1976, when the handgun ban was enacted.

Needless to say, this is completely useless. It’s two data points with absolutely no context.

My stats here are kind of an ass-pull, but they’re meant more as a demonstration of how fucking easy it would be to improve on the utterly useless, context-less numbers that CNN gave than a real analysis of the effect of the gun ban. I used two web-accessible sources, U.S. Census QuickFacts with historical census data and District of Columbia Crime Rates 1960-2006.

I strongly recommend following the last link in particular to show how completely asinine it is to use only two data points to judge the effect of the handgun ban. Anyway, here’s my comment:

As stated, this is a useless statistic, because it contains no information about either the population of Washington in the two years examined or about the total number of murders (regardless of weapon) in each year. Either one of those things would tell us something about the effect of the ban. The number of gun murders by itself, with no context of the city’s population or overall murder rates, tells us nothing.

The per capita rate of gun death for last year would be 143/572,059 (2000 Census) or about 2.5. The per capita rate of gun death for 1976 would be 135/702,000 (1970 Census) or 1.92. This doesn’t change the implication of the quote, but DOES provide actually useful information to the reader.

Also, there were 188 total murders and 135 gun murders in 1976, for a ratio of 71%. In 2006, there were 169 total murders. (Numbers for 2007 are not available.) Assuming no dramatic change in gun murders between 2006 and 2007, that gives a ratio of 86%. Again, this doesn’t change the implication, but it does provide more useful information about the overall murder/crime rate between the two years. (Murders actually went DOWN overall.)

But even this doesn’t come close to telling a full story, for a number of reasons. For example, there were 235 total murders in 1975, and in fact every year from 1969 to 1975 had more than 200 murders per year. The years 2004-2006, on the other hand, all had less than 200 murders, down from a peak between 1990-1993 which had over 450 murders per year. This clearly indicates that there is something OTHER THAN gun control legislation affecting the total murder rate. In fact, this factor, whatever it is, completely swamps any difference seen in murders between 1976 and 2006, which the article tries to pretend is a valid measure of the effect of gun control legislation in D.C.

Bottom line: quoting random numbers from random years doesn’t tell us anything. So don’t do it unless you’re willing to invest in a complete statistical analysis. (For the record, I haven’t done anything remotely like that here, but I did considerably more than the article did, and I didn’t spend more than 15 minutes doing it.)

New Hero: Dr. Richard Lenski

June 24th, 2008

Dr. Lenski is responsible for a truly awesome long-term experiment in E. coli evolution. His experiment plays a major role in Carl Zimmer’s awesome E. coli book, Microcosm, and he also gained some well-deserved fame for his discovery of an E. coli population in his experiment that had evolved de novo the ability to digest the citrate base the bacteria were grown in.

This incredible discovery, of course, has been pissed on by ignorant creationist assholes like Andrew Schlafly, the guy behind Conservapedia.

The great thing is that Dr. Lenski replied to the criticisms. His first response was gracious and took the effort to explain himself to Schlafly. Schlafly replied like the ignorant asshole creationist he is — i.e., by impugning Dr. Lenski’s credibility based on absolutely nothing at all. Dr. Lenski wrote a second letter, and while still engaging in a futile attempt at paedagogy nonetheless, er… responded in kind. As in, “kind of awesome”:

In other words, it’s not that we claim to have glimpsed “a unicorn in the garden” - we have a whole population of them living in my lab! [ http://en.wikipedia.org/wiki/The_Unicorn_in_the_Garden] And lest you accuse me further of fraud, I do not literally mean that we have unicorns in the lab. Rather, I am making a literary allusion. [ http://en.wikipedia.org/wiki/Allusion]

Gotta love somebody who includes Wikipedia citations in a snarky e-mail. PZ has the full letter.

Edit: Dr. Ben Goldacre (of the TAM shooting range story and also the catchy exclamation, “Fuck me, that is an astonishing amount of bacon.”) has the whole correspondence, including Andrew Schlafly’s two e-mails to Lenski.

Pretty Gosh-Darned Amazing

June 22nd, 2008

This doesn’t really top going to a shooting range with PZ, Ben Goldacre (on his first and probably last trip to America…), and Blake, but I got to meet Adam Savage this afternoon! Yeah, that one. He gave a great talk about his obsession with either obtaining or creating a perfect replica of the Maltese Falcon prop from the Bogart film of the same name, answered a question I asked about the plane on a treadmill debate (that was conclusively settled on the show, despite what anyone else says), brought a big box full of ping pong balls that they used to raise a ship, and then showed us some explosion porn.

See?

TAM freaking rocks!

Amazingly Surreal

June 21st, 2008

So. This afternoon, I found myself at a shooting range with PZ Myers, Dr. Ben Goldacre, and Blake Stacey.

File under “things I never expected to happen but are totally awesome”.

More Amazement!

June 20th, 2008

So, the first day of TAM has come and gone. Despite a bit of waffling in the afternoon when nothing was scheduled and Rebecca was busy interviewing people, it’s been pretty awesome so far. Blake surprised me by showing up; I didn’t realise he was going to be here. Also, I got to meet half of the Skepchick bloggers, including A Real Girl, Masala Skeptic, Carrie, Stacey, and Sam. I just need to meet Tracy and Donna* (neither of whom are here, sadly) to make a complete set!

Also, I got to hang out with PZ Myers and Phil Plait for a bit at the official TAM opening reception. I even got them to pose in a picture with me, and the universe didn’t collapse into a ball of strangelets or anything. See?

Me with PZ Myers and Phil Plait

* Edit: And also bug_girl and Vera and Amanda, it turns out! Maybe they’ll all come to the next TAM? ;)
* Edit: Crap! And Elyse, too! Ok, first I’ll sort out who’s actually a Skepchick blogger. Then I’ll meet them all.

Amazing!

June 17th, 2008

I find it difficult to believe that anyone I don’t already know personally reads this blog, but the site traffic stats suggest otherwise. So, in light of that, I’d like to point out that I’ll be attending The Amazing Meeting 6 at the Flamingo Hotel in Las Vegas this year. If anybody who reads is going, drop a comment. I’ll be at most of the Skeptic’s Guide events, as well.

From the “No Shit” Files…

June 12th, 2008

Apparently, the US Supreme Court has just ruled that Guantanamo Bay detainees must be given trial in civilian courts. To which I say, “no shit”. But, to have the Supreme Court saying the same thing is truly awesome.

But I’m mostly posting about it so I can point out that the Obsidian Wings headline for this story was the best ever: “Court Reaffirms Existence of Constitution“.

From the Files of Police Squad!

June 8th, 2008

Via Fortyseven comes this gem:

What’s the Beef?

June 6th, 2008

A random musing. Which pisses creationists off most about evolution, common descent or the lack of teleology?

I’m not in a good position to find an answer to that question, since I don’t know any creationists to ask. However, it seems to me that if there’s a genuine difference between IDists and classical creationists, it’s that the former are almost exclusively concerned with the question of teleology, whereas the latter, although obviously they enjoy their teleology as well, display more of a visceral disgust at the whole idea of common descent. “I Ain’t No Kin to a Monkey” wasn’t commissioned by the DI, after all.

It probably doesn’t mean anything in the long run, but I do wonder whether it’d make a difference if somebody started mining the DI’s output for arguments that accept common descent as a premise. I suspect enemy-of-my-enemy thinking would do well enough to keep the creationist/intelligent designer coalition together, but it might be fun for troll-baiting at least.

Tobasco da Gama and the Pillars of the Sky

June 4th, 2008

The clouds were a flat gray, spreading across the sky like a ceiling. The buildings of the city became pillars, seemingly supporting some larger structure of which the earth around was merely one of many floors, the city but one room in it.

Tobasco da Gama knew now that the simile had more truth to it than any of the city’s inhabitants would care to know. He came from a time when the greatest cities of the world had buildings made of wood and brick, few of which over three stories. Only the churches reached higher, like lightning rods to attract the electric energy God’s holy spirit and disperse it amongst their parishioners. Now, the churches were overshadowed by buildings devoted to commerce — a commerce that he and his fellow explorers had helped to build –, or to homes for the inhabitants of the city.

After all that he had seen since being untethered from his time and set adrift on the seas of history, human and inhuman, he felt this was appropriate. He knew that the old churches of man were just as insignificant in their rituals as the buildings were next to the sky-scraping office towers. He knew that the world beyond the world dwarfed those towers just as the towers dwarfed the steeples of the churches.

It was a difficult thing for a man who had dedicated his life half to amassing the profits of the world and half to spreading the word of God and of His Holiness, the Bishop of Rome, to admit. But admit it he must.

For the towers of the city had not provided him his first glimpse of pillars that held up the sky. He had seen the pillars on the outside, in the void, the Mists of Time, the place where the damnable Dragon of Time lived, the same creature who had torn him from his moorings in normal time and left him thus becalmed, waiting for the next current or wind to take him to ports unknown. In that place, there was no horizon in any direction, just a roiling chaos that defied human understand, a writhing nothing like the shapes one sees when there is no light to carry images to the eyes. But then, one day, after the currents in this Mists had flung him to some unknown time and place in the universe of physical things only to once again pull him back, as if he were nothing more than driftwood floating on the tides, he had seen the Pillars.

The Pillars contained within them the same chaotic nothing that formed the background everywhere within the Mists of Time, but nonetheless they had a clear definition, the pattern of the chaos subtly different within and without them. Tobasco could see no beginning or end to them. They simply extended into the infinity of the Mists. As he drifted, the Pillars barely moved in his vision, as though immensely far away, which meant they must also have been immeasurably huge.

That thought brought him little peace when he saw something moving between the Pillars. The Thing held no fixed shape, but it was different from the other chaos he saw in that place. It moved with intention. It was, in some sense of the word that no mortal man could possibly hope to understand, alive.

Tobasco da Gama then felt something he had felt only a few times before: fear. Because he understood that the Thing was looking back at him, into him, through him, and that it now began to approach, with almost incomprehensible malice. It was coming for him. It would devour him.

Just then, in that moment of realisation, he suddenly felt the tug of the currents in the Mists pull him out and back into the physical world. It was then that he found himself in the midst of the city, pondering a different set of pillars in the sky.

He then had a second realisation that felt like the removal of a heavy burden or the first draught of fresh air a man breathes after nearly being suffocated by smoke.

If the Thing moved with intention, then it followed rules. It was bound by them as surely as he was now bound to the earth by its gravity. The rules might be forever beyond his understanding, the limits out of his reach. But the Thing had limits. The Dragon of Time must have them, too.

They could be fought.