This is a very valuable article. It spotlights something I hadn’t noticed: the government has been speaking in terms of “average dose” from the scanners.
Now, I’m a scientist, and I used to TA for the statistics courses in grad school, and I’m here to tell you that politicians and bureaucrats just LOVE the statistic known as the average, because it’s so handy for demagoguing an issue. You can select your data-set to say whatever you want to say. Consider the following sequence of numbers:
1, 1, 1, 10, 1.
The “average” is nearly 3. But how representative of the set is that? If you were to pick a number most typical or representative of the set, I doubt you’d pick anything close to 3. The singular value of 10 is clearly some sort of fluke. But the tendency of the average to be pulled in one direction or another by fluke data-points is one of its most useful features for those who wish to obscure the real meaning of data.
Keep that in mind when reading this guy’s blog post.
Those sons of bitches.
I just read your post again, after linking the whole thread here, and thought of another funny example:
The average voltage in a common house outlet is zero. But try to stick your fingers into it :-)
Hint: the AC voltage is positive half of the time, and negative other half of the time. The average is zero. But the peaks will kill you.