Statisticians should not listen to talk radio or to anything on the Fox network. Those people who say that you can prove anything with statistics are mistaken. You can prove anything with statistics to people who don’t understand statistics. I think some of those same people you can prove anything to with a box of doughnuts.
So, last night we were listening to someone talking about the health care debate and for the umpteenth time it was brought up that,
“If Obama’s bill passes, we’ll have socialized medicine, JUST LIKE IN CANADA!”
What’s with all the hating on Canada all of a sudden? Have these people ever been to Canada? They make it sound like it is full of health-care preventing unlicensed physicians looking to give lethal injections to your grandmother. Seriously, the scariest thing you can think of is that we’ll become Canadian? Now, if they had some evidence that government health care (which, by the way, what do you think Medicare is) causes cold weather, I would vote against it.
However, the latest argument that really set me off was when someone pointed out on one of these shows,
“You know, Canada actually has a life expectancy a couple of years longer than the U.S.”
[I verified this fact on that source of all knowledge, wikipedia.]
Did overweight, overpaid talk show host at this point stop and say,
No, he did not. He said,
“Well, you can’t compare the two. The U.S. has a population ten times that of Canada. So, there are ten times more homicides, ten times more accidents.”
At this point I began yelling at the TV,
“YOU MORON! That would mean the absolute NUMBER of deaths due to those causes is higher. Don’t you know the difference between a frequency and a percentage?”
My husband, a.k.a. the calmest person in the world, as evidenced by his 12 years of marriage to me, said,
“Well, that must be conservative math. It must be different than liberal math.”
“There is no such thing! There is only math. That is why I specialized in statistics, for God’s sakes! So I wouldn’t have to have stupid arguments with people on whether the square root of the variance was the standard deviation in Tibetan culture or if it was a male chauvinist standard deviation. It just IS. If you have ten times as many people and ten times as many homicides, your rate of homicide is the SAME. Besides, we have way more homicides than Canada!”
This argument was settled by my husband making me a martini, with olives, and agreeing with me.
By the way, what is it with all this Canada-bashing all of a sudden. It used to be that high on the list of “stuff white people like” was threatening to move to Canada. I noticed that all of these conservative math advocates are white. Where are they going to threaten to move to now?
Being a Type-AAA personality, in addition to running the Julia Group, I have a ‘day job’ as a statistical consultant at a university where the communications people shudder as they walk by me. (I love the title of the book Molly Ivins Can’t Say That Can She? Simply because it reminds me of the reactions I get just going through life.) Hence, this blog is hosted by The Julia Group as Julia could care less what I say as long as I pay her phone bill enabling an unending stream of text messages to everyone short of God, whose cell phone number she has been unable to learn – yet.
Oh, speaking of The Julia Group, we’re booked through September, 2010. I am doing as much work as I want to do and I am not interested in hiring you and getting more work for you to do. Don’t call me or ask me to be your friend on linked in or any of those things. If you do need statistical consulting after September, 2010, though, look me up.
Where we were – oh yes, statistical consulting at the university. Much of job entails telling, or at least hinting, things to people that they don’t want to know. Before that I was a professor teaching statistics to people who didn’t want to learn it.
A nice part of my job, though, is I get paid to read books and look things up on the Internet. As my grandmother told me about my post-doctoral research, which was essentially the same thing, with some journal article writing thrown in, and at much lower pay,
“Mija, reading books and talking about them is not a job. It is what people do after their job to relax. You better go back to whoever hired you at that university and ask. There’s got to be more to it than that.”
Here is one thing people don’t want to know – when you glance at your data, find two groups have a substantially different mean and then do a planned comparison as if those are the only two groups you ever thought of comparing, what you have REALLY done statistically speaking is all possible pairwise comparisons and then selected out the two groups that were different. You really ought to use the Tukey or other test that does all possible comparisons, suck it up and take the error rate and level of significance that goes with what you really did. The fact that you ‘eyeballed’ it versus running the Tukey first doesn’t change anything.
But you’re not going to listen to me, are you? No-o-o , you are going to go ahead and do a t-test between those two groups aren’t you? Fine! Don’t say I didn’t warn you.
On a positive note, though, when I run across a website that talks about statistics, it is like finding a friend. Yesterday, I was looking for a book on statistics with SPSS and I found 42 “Introduction to — ” and “Getting started with — ” all the way back for 12 versions. I cannot imagine what I need less than a book entitled “Getting started with SPSS 8.0”. A mushroom brush, maybe?
So, I was very happy to find this website by David Howell where he discussed multiple comparisons with repeated measures, among other things. It wasn’t what I was looking for, really, but I think most of what I have learned in life occurred when I was actually looking for something else.