Tuesday, September 18, 2007

The Roe Effect: How NOT to perform a Study

Wow. Please read http://www.opinionjournal.com/extra/?id=110005277.

This is an awful study and a great example on how one can twist numbers into a "good story." There are so many things wrong with it, I do not know where to begin. I am only going to point out a few... In fact, this would probably be a study I would hand to students to dissect and tell me what they think is wrong. Their issues are typical of bad statistical analysis. You could point out their mathematical flaws for eons. However, their very construct is wrong. They assume a cause and affect relationship.

1) They mention that children "tend" to absorb ideals of their parents...yet they analyze as it is a cause and effect relationship...that they WILL absorb ideals of parents.
2) N=1. "Hey, I know this guy who thought everyone was like their parents so they MUST all share the same political views"
3) Wow, they really cleaned up the issue that always arises of getting the right demographics by asking people if they "knew of anyone..." What a great and cheap way to control for the demographics factor. I wish I had thought of this in the past. Would have saved me oodles of time! Then, again, they assumed cause and affect saying well, those that answered yes must have had the same political leanings so that MUST mean those who they answered yes about had the same political views...they even go so far as to say that 1/3 of liberals are having more abortions...hmm, based off of..."I know someone?"
4) The "significant difference" badge of honor. Love that one...since there was a "significant difference" it must be true...even though everything they did was wrong before that.
5) Finally, they also assume those with abortions will even vote. They did not even take into account the voting percentage of those likely to vote!

Bottom line...asking people if they know someone that had an abortion, and assuming that the person who did have an abortion followed the same political leanings, and then again assuming that if so, these aborted individuals would B) Most definitely Vote and B) Most definitely have the same political leanings is one of the biggest stretches I have seen in a very long time.

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