Hall vs. Florida: IQ, the death penalty, and margin of error (edited 5/27/14)

Here is Think Progress' story about a U.S. Supreme Court case that hinges on statistics. The case centers around death row inmate Freddy Lee Hall. He was sentenced to death in Florida for the murder of Karol Hurst in 1978. This isn't in dispute. What is in dispute is whether or not Hall qualifies as mentally retarded and, thus, should be exempt from the death penalty per Virginia vs. Atkins.

So, this is an example relevant to any number of psychology classes (developmental, ethics, psychology and the law, etc.). It is relevant to a statistics class because the main thrust of the argument has to do with the margin of error associated with the IQ test that designated Hall as having an IQ of 71. In order to qualify as mentally retarded in Florida, an individual has to have an IQ of 70 or lower. So, at first blush, Hall is out of luck. Until his lawyers bring up the fact that the margin of error on this test is +/- 5 points. This is a good example of confidence intervals/margin of error in a very high stakes situation.

If you want to hear the very statsy oral argument, listen to it here. It is interesting to hear a fairly simple statistical construct (standard of error) described as by a lawyer. Frankly, it is unsettling to listen to the lawyer try to explain statistics. He conflates standard error and standard deviation doesn't understand what 95% confidence means.

Edited 5/27 to add:

"Held: The State's threshold requirement, as interpreted by the Florida Supreme Court, is unconstitutional. Pp. 5-22." (meaning, the current IQ standards at which a person would be executed is considered unconstitutional)

Read the rest of the Supreme Court's decision here. It prominently features the problem of the standard error of measurement (margin of error) and the limitations of IQ testing in the decision. You can read APA amicus briefing about this case, IQ testing, and standard error here.

Comments

Ways to use funny meme scales in your stats classes

Have you ever heard of the theory that there are multiple people worldwide thinking about the same novel thing at the same time? It is the multiple discovery hypothesis of invention . Like, multiple great minds around the world were working on calculus at the same time. Well, I think a bunch of super-duper psychology professors were all thinking about scale memes and pedagogy at the same time. Clearly, this is just as impressive as calculus. Who were some of these great minds? 1) Dr. Molly Metz maintains a curated list of hilarious "How you doing?" scales. 2) Dr. Esther Lindenström posted about using these scales as student check-ins. 3) I was working on a blog post about using such scales to teach the basics of variables. So, I decided to create a post about three ways to use these scales in your stats classes: 1) Teaching the basics of variables. 2) Nominal vs. ordinal scales. 3) Daily check-in with your students. 1. Teach your students the basics...

Using pulse rates to determine the scariest of scary movies

The Science of Scare project, conducted by MoneySuperMarket.com, recorded heart rates in participants watching fifty horror movies to determine the scariest of scary movies. Below is a screenshot of the original variables and data for 12 of the 50 movies provided by MoneySuperMarket.com: https://www.moneysupermarket.com/broadband/features/science-of-scare/ https://www.moneysupermarket.com/broadband/features/science-of-scare/ Here is my version of the data in Excel format . It includes the original data plus four additional columns (so you can run more analyses on the data): -Year of Release -Rotten Tomato rating -Does this movie have a sequel (yes or no)? -Is this movie a sequel (yes or no)? Here are some ways you could use this in class: 1. Correlation : Rotten Tomato rating does not correlate with the overall scare score ( r = 0.13, p = 0.36). 2. Within-subject research design : Baseline, average, and maximum heart rates are reported for each film. 3. ...

Andy Field's Statistics Hell

Andy Field is a psychologist, statistician, and author. He created a funny, Dante's Inferno-themed web site that contains everything you ever wanted to know about statistics. I know, I know, you're thinking, "Not another Dante's Inferno themed statistics web site!". But give this one a try. Property of Andy Field. I certainly can't take credit for this. Some highlights: 1) The aesthetic is priceless. For example, his intermediate statistics page begins with the introduction, "You will experience the bowel-evacuating effect of multiple regression, the bone-splintering power of ANOVA and the nose-hair pulling torment of factor analysis. Can you cope: I think not, mortal filth. Be warned, your brain will be placed in a jar of cerebral fluid and I will toy with it at my leisure." 2) It is all free. Including worksheets, data, etc. How amazing and generous. And, if you are feeling generous and feel the need to compensate him for the website, ...

Search This Blog