Wednesday, September 02, 2009


Lies, Damn Lies and a Little Pseudo-Science

"Lies, damned lies, and statistics" is attributed to Benjamin Disraeli. A very good quote.

Recently, steve2 launched a discussion into misleading statistics. Coincidentally, I came across
an excellent video on how common mistakes in statistics mislead juries that I found through Right on the Left Coast. (It's strictly coincidental that the example Peter Donnelly uses involves a doctor.) In this case, the mistake was the difference in a murder conviction and being found innocent.

Also discussed in the video are the possibilities of a series of head, head, tails vs. head, tails, heads while flipping a coin a number of times, such as 100 consecutive flips. A twenty minute video but keeps you entertained as well as informed.

I found this page of12 puzzles on misleading statistics gives a good overview of various ways statistics can mislead. Are octogenarians the safest of all drivers? Read and find out.

Looking into the realm of pseudo-science we unexpectedly find forensics. The cover story of the August, 2009 issue of Popular Mechanics is CSI Myths: The Shaky Science Behind Forensics. After years of all the various CSI episodes and versions, we thought murderers could be identified from vapor left behind from their breath. It turns out much of what we've been led to believe was solid science isn't.
The faulty identification that sent Brown to prison for 15 years may seem like a rare glitch in the U.S. criminal justice system. It wasn’t. As DNA testing has made it possible to re-examine biological evidence from past trials, more than 200 people have had their convictions overturned. In approximately 50 percent of those cases, bad forensic analysis contributed to their imprisonment.

On television and in the movies, forensic examiners unravel difficult cases with a combination of scientific acumen, cutting-edge technology and dogged persistence. The gee-whiz wonder of it all has spawned its own media-age legal phenomenon known as the “CSI effect.” Jurors routinely afford confident scientific experts an almost mythic infallibility because they evoke the bold characters from crime dramas. The real world of forensic science, however, is far different. America’s forensic labs are overburdened, understaffed and under intense pressure from prosecutors to produce results. According to a 2005 study by the Department of Justice, the average lab has a backlog of 401 requests for services. Plus, several state and city forensic departments have been racked by scandals involving mishandled evidence and outright fraud.

But criminal forensics has a deeper problem of basic validity. Bite marks, blood-splatter patterns, ballistics, and hair, fiber and handwriting analysis sound compelling in the courtroom, but much of the “science” behind forensic science rests on surprisingly shaky foundations. Many well-established forms of evidence are the product of highly subjective analysis by people with minimal credentials—according to the American Society of Crime Laboratory Directors, no advanced degree is required for a career in forensics. And even the most experienced and respected professionals can come to inaccurate conclusions, because the body of research behind the majority of the forensic sciences is incomplete, and the established methodologies are often inexact. “There is no scientific foundation for it,” says Arizona State University law professor Michael Saks. “As you begin to unpack it you find it’s a lot of loosey-goosey stuff.”
It turns out forensic science was not developed by scientists and often has little scientific foundation.

Visiting the blog of my longest blog friend, Cousin Pat at Hurricane Radio, I found a tragic example of failed forensic "science" from New Yorker magazine. This is the story of Cameron Todd Willingham convicted for setting his house on fire and killing his children in the process. Willingham refused to cop a guilty plea in exchange for life in prison rather than a death sentence. Maintaining his innocence, he refused.

Cousin Pat, not actually my cousin, points out the New Yorker article as "what real journalism looks like." Indeed, it is. A well written tragic story. The last paragraph:
Just before Willingham received the lethal injection, he was asked if he had any last words. He said, “The only statement I want to make is that I am an innocent man convicted of a crime I did not commit. I have been persecuted for twelve years for something I did not do. From God’s dust I came and to dust I will return, so the Earth shall become my throne.”
Did Texas execute an innocent man? It sure looks that way.

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