Slashdot Mirror
How Well Do You Estimate?
A random UK blogger has published a quiz asking readers to estimate various numeric values which they may or may not have knowledge of; and has analyzed the resulting answers to determine how well people guess. The first part of the results looks at some specific questions, and the second part takes a look at the quiz overall.
With 44.7% accuracy!
more or less.
I am one of many. My idea is not unique, nor do I expect my voice alone to sway you. I speak in a chorus of opinion.
I would estimate that that server stayed up less than 2 minutes after the story was published. Mirrors anyone?
Reminds me of the joke...
Why can't girls measure distances?
(Holding up a pinkie)
Because they've been told that THIS is 6 inches all their life.
AC
I estimate that at about this point all the jokes about estimating will get tedious
Philip
Signatures are broken
Reminds me of a bit of training from my army days.
If you have difficulty estimating a distance ( range), divide the distance in two, and try estimating that.
This sounds stupid, but actually works. Well, it worked for me. I'll never forget how I laughed in my head at the suggestion, and my astonishment at it actually working.
Mike.
Part 1
Part 2
I used to work at a small datamining shop. The people there were very bright, some of them quite famous in the fields of statistics, number theory, etc.. One day, we were sitting in the front room of our offices having lunch, chewing the fat, as it were.
At lunches, we would sometimes try to stump our CTO a grey beard who is famous for work in information theory and general genius. We had never succeeded, even with obscure questions in biology "How do Prions work?", physics "What order are the colors of the rainbow, and why?", "How does the Corriolus effect work?", etc. that none of us had any particular knowledge of, and always had to research afterwards to determine the correctness of his answers.
So, I posed the question to the group "How many leaves are on that tree outside the window?" It was a ~30 foot tall, bushy tree in the height of summer. I hoped he'd take the bait.. I thought this was going to be very hard to "get right", and it would even be difficult come up with a plausible answer.
After a few moments, I set off the responses by saying that I thought it easily had 10k leaves, possibly 20k or more.
Everyone gasped. "Oh no! No way..." and then proceeded to offer lower and lower estimates.
The responses started with me and made their way up in the seniority ranks (I was the most junior) all the way up to the CTO. He said "Oh! those kinds of things are notoriously hard to estimate. We typically overestimate grossly in counting things of plentitude. Oh, I don't know. 200?".
Finally we had him. There was no way there were 200 leaves on that tree.
Later, in discussion, a trend became clear. The more senior the person, the more conservative was their response, even to the ridiculous level of our CTO saying a tree in full flush, that he could see right outside of the window, had 200 leaves, when it most plainly had many, many more.
Anyone want to hazard a guess? How many leaves on say, an adult Sycamore (or Maple, Oak, etc.)?
They spend a lot of time on grouping. For example What is 97 + 198? I was taught to add 8 and 7, carry the one etc...
They are taught to group the numbers, the instantly recognize that the answer is close to 300, then see how it differs from the 100s. 97 is 3 less, 198 is 2 less. Now add the 3 and 2, getting 5.
The answer is of course 300 - 5, or 295.
I find this method very intuitive.
On a side note, there are many errors made when newspapers, magazines, etc. estimate numbers. Sometimes they will round values before presenting the final number, causing a huge difference. Or they will give some value like $6,021.50 when some of the values have only two or three significant digits. Or they'll make some hideous stats error such as adding two means together and not weighting the scores appropriately. An excellent book that discusses this is John Allen Paulos' "A Mathematician Reads the Newspaper."