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.
I estimate that I would end up somewhere in the middle.
I don't know.
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?
5 comments before the server collapses under the slashdotting. Pretty close?
If construction was anything like programming, an incorrectly fitted lock would bring down the entire building...
about 1 minute and 10 requests...
who the hell is Tony Benn by the way ?
Google passes Turing test : see my journal
Fascinating Read
Life is the leading cause of death in America.
that I will get a +3, funny
Don't waste your vote! Vote for whoever you want, unless you live in a swing state it won't matter anyways
Server timed out trying to contact ex-parrot.com.
Looks like we've got an ex-webserver on our hands.
.
.
"It's not dead, it's IIS!"
Does nobody here on Slashdot even remember the Mythical Man Month any more? The section on estimation and back of the envelope calculations (which I wouldn't be surprised if this blog pulled from, but I can't tell because its slashdotted already) was quite enlightening. Its main point was that people were way too confident in their estimates, even when they would admit that they had no idea.
You're special forces then? That's great! I just love your olympics!
I'll estimate that in about an hour there will be 347 replies posted, about 10 of which will be +5 insightful and, oh, maybe 13 +5 funny.
Oh, yeah, it's not easy to pad these out to 120 characters.
I guestimate that the server will be down for the next 30 minutes +/- 1 day....
that we'll end up with about 30 comments about how fast the site went down due to slashdotting....
I'd estimate that I made it to, oh, say question 24 before the story went live and site died as fast as you can say "Please estimate the air speed of an unladen swallow"
--
I write stuff, but not that well and not that often...
I can usually estimate within plus or minus one or two Libraries of Congress every time.
I actually just finished this book. It's an oldy but goody, and it should be required reading for the statistically challenged. (I.e, those subject to the whims of marketing droids)
Take it easy? I'll take it anyway I can get it . . .
Most folks are 70% correct, at least 30% of the time.
give us mirrors!!!
I own a pump action golf ball cannon. I made it myself.
ISP bill this month, but of course, this is only an estimation.
I estimate that at about this point all the jokes about estimating will get tedious
Philip
Signatures are broken
google cache of second link http://216.239.39.104/search?q=cache:DB1CxyRtiNsJ: ex-parrot.com/~chris/wwwitter/20040903-but_i_wore_ the_juice.html+ex-parrot.com+/~chris/wwwitter/2004 0903-but_i_wore_the_juice.html&hl=en&start =1
People can find statistics stating anything. 33% of all people know that.
No one cares what your captcha was
Houston TX, USA
Everybody in the IT industry knows that no matter how well you estimate, it'll always take twice as long.
I'm currently taking a course at my school, for essentially doing computations, but only up to a certain accuracy (estimation with precision). We basically build algorithms, that are normally simple enough to follow, and then just repeat the process until the desired precision is reached. There are multiple ways to do estimation. Like for square roots, you can actually used Fixed Point Iteration(x = g(x)), where g(x) = (x+x/n)/2, where n is the integer of the square root. Just continue that process for about 5 times, and the results are amazing.
je suis parce que j'aime
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.
Anyone want to estimate how long before the site gets /.'ed?
Ooops, too late....
Part 1
Part 2
Here
that the website will get /. ed you insensitive clod
Never underestimate the power of idiots in large groups
that there will be a lot of bad jokes about estimation.
I estimate the site to be toast in about 1 second.
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.)?
To clear up:
Estimate: To calculate approximately (the amount, extent, magnitude, position, or value of something).
Guess: To predict (a result or an event) without sufficient information.
Predict: To state, tell about, or make known in advance, especially on the basis of special knowledge.
Based on these definitions, different people would either guess or estimate (or state / predict) (the known value of) the distance between Edinburgh and Cardiff.
I saw his nice graph, looks like SPSS.
#hostfile 0.0.0.0 primidi.com 0.0.0.0 www.primidi.com 0.0.0.0 radio.weblogs.com
that should be +1, ironic
Don't waste your vote! Vote for whoever you want, unless you live in a swing state it won't matter anyways
-- Thou hast strayed far from the path of the Avatar.
The article's slashdotted, so I'm not sure what this is all about. But I've always prided myself on my ability to estimate time and miles. Frequently, I'll look at my watch and find it's, say, 3:00. Some time later I'll estimate that it's 4:22, look at my watch, and find it's 4:20.
Similarly, I will look at the odometer in my car, drive a distance, and guess that it's 10 miles later. Looking down, 10.1.
The best is when you combine them. "How long before we get there?" the wife asks. "About 47 minutes," say I, and 47 minutes later arrive at our destination.
I note this only because most everyone else seems incredibly bad at this. As when someone gives you loose directions to a place like this, "Oh, go about 3 miles, then turn left on Main St." Half a mile later I'm slamming on the breaks 'cause I just past a sign saying "Main St." Or when they tell you it's a 5 minute drive, when it's really 15. Drives me batty.
In short, I estimate that just about everyone sucks at estimating. Funny thing is people always over-estimate distance and under-estimate time.
... I'de have to say well to-QUITE-well.
Remembering that you are going to die is the best way I know to avoid the trap of thinking you have something to lose.
You're right, I'm sure. Damn. That's what happens when you have two possible places to work, and only one copy of each of your favorite compuCulture books. Thanks for the correction.
You realize that now I'm going to have to reread both of them this weekend, don't you?
You're special forces then? That's great! I just love your olympics!
I've always had trouble making estimations. With new work, it's not too bad. But when modifying existing systems or doing integration I find it damn near impossible to create a semi-accurate estimation without having a whole lot of experience with the involved subsystems (which is rare).
The problem is that 1) you can't make an estimation unless you understand the problem and 2) understanding the problem is 80% of the work of solving it.
Yeah, I know everybody is after funny mods, but you don't "estimate" a future event, you predict it.
Estimation is making an educated guess at a quantity without scientifically measuring it, usually with some sort of observation.
"I reckon thats 8 inches long and 2 inches thick."
Prediction is using past experience to state that an event will happen.
Norman Cook's Ode to Sl
The server seems to be slow but eventually responsive, so I got a peek at the results and part of the test.
When Poindexter tried to set up a terror gambling pool to predict terror events, he was relying on something like this-- that collective knowledge would somehow converge on the right answer, or something close enough to be useful.
The results from this survey suggest that that's probably true for something where the guessers/bettors actually have some real knowledge, however deeply buried in their memories it might be, but in areas where people have no information (the GDP), or worse, have been hearing sensationalized opinions (average amount that people get on the dole), they can be not only wildly wrong, but have no idea how wildly wrong they can be.
The terror pool gave me the impression that it was going to collect and integrate the wild ass guesses of its members to somehow develop predictions, but it wasn't clear that anybody would have anything better than WAGs, making it possibly of negative value, rather than providing the collected wisdom that was intended.
A sort of trivial example is if I ask a bunch of people to guess the number of jellybeans in a jar. If I show them the jar, the mean guess will probably be pretty close to the true value. In this case, each person is making an estimate based on seeing the beans and the jar.
If I don't show them the jar, or tell them anything about it, they can only make wild guesses, and I could have a tiny jar with a single jellybean, or a jar the size of the Rose Bowl with however many jellybeans that holds. In this case they're making guesses rather than estimates, and the statistics won't tell you anything about the number of beans in the jar (but may tell you something about how the guessers think of jellybeans and jars).
They should have estimated a better webserver before their their site was on slashdot...
As almost every single comment up until now talks about personal experiences or makes stupid jokes, I'm going to critique the method he uses to score an answer. From the second link (find a google cache of it to read it) you can see that he treats each answer and estimate of the accuracy of the answer as a single question - you get a single score from both. I think this approach is fundamentally flawed. Why not instead score the guess (with some sort of algorithm like the one he uses) and then score the guess of accuracy by the same method. Then if you want a single number, add the two together. Right now if you guess well and guess your accuracy perfectly, you get zero points. That is completely out of whack. Instead, using my way you score the best possible score when you guess perfectly and perfectly guess your accuracy, and the worst possible score when you guess horribly and horribly guess your accuracy. The scores move between those two extremes rationally too. As he wanted people who guessed zero error (thought their guess was a perfect guess) to get no points, he obviously had an agenda - that people should be penalized for thinking they are perfectly right. In no way is this an unbiased or useful test.
I submitted this story last night, and it didn't get posted.
He's not so random, he was the man behind the Political Survey.
Struggling to find a day everyone can make? WhenShallWe.com
I guess it depends on if the chute opens or not
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.
My father, a long time IT guy since '63 or so, told me when estimating a project development time take your original SNAP off the top of your head guess , double it , then double it again.
While I wont say its perfect it comes darn close when you take into account all the administrative overhead, meeting, decisions, etc.
And since MOST of us developers have a good idead of what our real capablities are. We want to blurt out an ego answer to ourselves, yeah 50 hrs, and if we were in a cage locked up with NOTHING else to do we probably could do it in that timeframe, but bathroom caffine breaks etc take their toll, errr troll
half of the time I'm almost always pretty close to the correct.
Free Scotland!
I don't understand this. Agnosticism is pretty much summed up by the statement, 'One cannot know whether or not god exists.' This is a positive belief, a belief that it is impossible to know something. This seems very far away from a scientific view. A scientist would say, surely, that it should be possible to establish the existence of god if god exists, and that if there's a lack of proof, one should assume god does not exist. (Of course, many will say that there is plenty of evidence of the existence of god, that is outside of my argument here). This view is pretty much the antithesis of agnosticism.
Am I misunderstanding your sig? Or perhaps, you don't really mean 'agnostic', you actually mean 'weak atheist' and I am being too pedantic over exact meanings.
Oceania has always been at war with Eastasia.
People at large seem to lack important estimation skills. In my observation, people seem to consider a billion, million, and trillion more or less the same. In a December 2003 issue of Vanity Fair, Graydon Carter estimated the U.S. Budget deficit at 6.4 quadrillion dollars. To anyone with an actual understanding of such a number, that figure is completely ludicrous - but it went unoticed by the editors.
We need increased numerical literacy - so that people understand just how much money 1 million vs. 10 million vs 100 million etc etc actually is. I'm sick of hearing someone say 'are you aware that we spend $x billion dollars a year on thing y?' and then expect me to be outraged or surprised. They just think that 'billion' sounds like a lot - but would they have the same response if it were $x*100 million, or $x*10 billion?
My blog
"We give him about a 50-50 chance of living... and of course, there's only a 10% chance of that."
How long is a piece of string?
RTFM; please, I beg you.
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."
I propose a test: try to summarize the article. /just too lazy to read.
I estimate that too many people will start off their stupid posts with "I estimate..."
Er, wait...
Finally a resolution to the great lunch question!
And, I probably had the closest estimate! The tree we were looking at was nowhere near as big as an Oak.. so maybe it was half to a tenth as many leaves. Who knows, who cares? I see thousands in that paper. w00t.
High school math teachers everywhere quake in yer boots!
If that was the case, I'd say I over-estimate for the most part.
10, 12 inches... that's it!
Get your Unix fortune now!
A former co-worker was telling us about some of her tutoring experiences. She was helping some high school kids with the concept of estimation. She looked at the ceiling and said you could estimate that it was about 10 feet high. She told them that "the great thing about estimation is that it doesn't have to be the 'right' answer."
So she pointed a car parked nearby and asked one of the students how far he thought the car was. His reply, "50 gallons."
Incredulous, she said that his answer didn't make sense.
"But that's the great thing about estimation! It doesn't have to be right!"
-- Don't Tase me, bro!
You would be describing the difference between localized perception and overall truth, the essential gap between concept and reality.
For example, I can look at the North American business market and go "Wow! Microsoft owns this market!" because all I see is Windows on the desktops.
But in truth, it is the back-end data servers from a myriad of companies and providers which are entrusted with the critical business information, not the desktop. The desktop is merely an access point and a collection of utilities to help people analyse and format that information.
I do not fail; I succeed at finding out what does not work.
I estimate I am the first person to attempt a short joke on my estimating abilities.
(I know, repetitive. So what, gimme a break that's kinda the point)
parallel computing!!!
The war with islam is a war on the beast
The war on terror is a war for peace
It turns out that I estimated poorly about moderators getting the joke about how poorly I estimate how well I estimate, and furthermore, estimated poorly about how well I estimate my estimations.
I estimate we've all learned something today.
Suprisingly, when I look at normal statistics, half of it falls above the average. In a crazy coincidence, half of it occurs below the average!
Estimations are funny. I estimate that the average person has average number of legs. But actually, the average person, has more than the average number of legs.
I have no idea why I made this post.
Yes, that is a good method, but it's only good in a limited number of cases. What 72 + 137? You don't get the correct answer of 209 quite so easily, unless you estimate to 10's and 5's, or 10's and 25's. Not nearly as simple.
;)
The method I used, but wasn't exactly taught in school, was to consider it as a quantity and move items from one to the other. In your case, I would have most likely moved 2 from 97 into the 198. Thus making a pile of 95 and a pile of 200, which is easy to add, obviously. This works for the 72+137 problem as well, albeit slightly more complicatedly: Move 3 from 137 to 72, giving 75 and 134. Now move 25 giving 100 and 109. The 109 is arrived at in the head because you're taking away 25 from 134, and that's 134 - 24 - 1 (same moving things around process as adding, but with reversed signs).
It's simpler to do in the head than it is to explain in words, because really you're thinking of piles of objects and moving them around. Think of subtractions as a hole in the ground that can hold so many, and moving that many objects from the pile into the hole. Helped me when I was learning that stuff when growing up, anyway. I believe I was 6 at the time.
- Give a man a fire and he's warm for a day, but set him on fire and he's warm for the rest of his life.
Just because you make an arbitrary cutoff at 2.0, that doesn't suddenly shift the distribution to be recentered around the center of the new range.
For example, if you don't allow people with below 100 IQ to enter a room, the average IQ of the room will be higher than the average IQ of the human population. But the average IQ of the room will still be closer to 100 than, say, 125 because there are many more people With an IQ of 100 than people with an IQ of 150.
If you want a vision of the future, imagine a youtube comments section scrolling - forever.
I got 7 of 12 :)
You will never "find" time for anything. You must "make" it.
Please estimate the following:
/. the article. /.ers that actualy took the quiz, which eventualy led to the event described in question #1. /.ers from question #3 that will most likely reply, "I'm not British, you insensitive clod!"
1. The amount of time it took to
2. The number of posts asking you to estimate question #1 above.
3. The number of
4. The number of
I estimate the number is >= (-1 * Infinity^Infinity)
If something is so important that you feel the need to post it on the internet... It probably isn't that important.
When I started remodeling of my house the parents of a friend of mine gave me a great estimation method that has proven to be true.
Take your best guess, double it and move up to the next time unit.
So, a 1 week job becomes a 2 month one.
So far I'm 1.75 years into a remodel that I thought would take 6 months -- I hope to god it doesn't take 12 years, but it is starting to feel like it.
Some of the questions in the quiz are not suitable for estimation.
For example answering "the year that Harold II became King of England" requires knowledge of English history. Any answer prior to the mid 1900s is a reasonable one for a person who only knows about Queen Elizabeth II.
People with more knowledge know this a pre-Norman Conquest King and so the answer must be before 1066. But that reduction in the scope of the answer comes from existing knowledge not by estimating.
...he didn't go to college.
bush vs kerry
The war with islam is a war on the beast
The war on terror is a war for peace
I always state my estimates using the word "this":
this big, this long, this tall, this thick...
Most Slashdotters should love the fellow who did this quiz!!! http://ex-parrot.com/~chris/moral.html
Don't blame me -- I voted for Roslin.
This issue has been studied for many decades in order to help organizations minimize losses on bad bids. Courses are taught on this. I took something like this once. There was an exercise to estimate the number of beans in jar. People's guesses fell along a curve called the binnormal distribution. From this equation you can estimate the best price to offer versus other people's bids in order to ocassionally win and make money at it.
You are required to make a guess and give a plus or minus value.
For many questions, people may be 40% sure that the answer is either 9, 10 or 11, but there is a thirty percent chance that the answer is 5-8. Maybe the person percieves a 1% chance that the answer is 12 or higher and a 29 percent chance that it is 0-4.
The person taking the test would likely instinctively guess 10 as their answer, but then realise that +- 5 contains the range 5-15. Then they say: hmm. What number is in the middle of the range that has a 70% probability of being correct, that is 5-11? 8. So the answer is 8 +- 3. But most people would put down 10 +- 5 just because they didn't want to do the math to figure out how to enter their guess into the survey, and get a score lower than their estimation.
It would be easier for test takers to provide a range with a max and a min, and no guess. that way they don't have to do math to figure out what their optimal guess should be.
However, you could have someone who is 100% sure the answer is either exactly 12, exactly 120 or exactly 1200. Their optimal guess would be ( 12 + 1200-12/2 ) +- 1200-12/2. However, they know the answer is certainly not 13. Letting a person specify multiple ranges whose probabilities of being correct sum to 70% seems to make sence. Then someone can say: It's either 100-105 or it's 3000-3100, But it's not 106-2999.
There also needs to be a "I have no idea whatsoever". It shouldn't decrease a person't score. For instance, I had no idea what an MP was in the House of Commons. Likewise exact answers should be discounted from test results - there is no estimation going on then. Don't tell the test takers that being exact will lower their score though. Then they'd just put down a very restrictive range.
and uncertainty- Doug Adams A stopped clock is correct twice a day. The article does not come to any important conclusions. In other words what is the point?
0 during 6 months of the year for deciduous trees.
Reminds me of some work done by psychologists Kahneman and Tversky (Kahneman went on to win the nobel prize in economics for different studies). In their studies they had people do things like this (e.g., what year was the constitution adopted by the states). Supplying "anchors" influences your judgement. For example, supplying the anchor that the articles of confederation were ratified in 1781 (I think) would shift the answer toward 1781 compared with the case in which the anchor was that George Washington left office in 1796. The idea is that if you know a.) that the constitution came after the articles of confederation and b.) that the constitution was ratified before Washington left office, you will use specific dates associated with those events to anchor your answer.
i read the article, and i find it amazing and mindboggling that if you average all the guesses of the number of jelly beans in a jar, you come up with an answer that is very close to the actual number.
each person who tries to guess the number has the same information as the next person. moreover, this information is *very limited*!! i mean, everyone is allowed to only look at the jar! how is it that the right answer can emerge from averaging a bunch of more-or-less random guesses?!?
of course, jelly beans are just an example--i am obviously more interested in the phenomenon that is illustrated by the that example.
someone please enlighten me.
But on a more substantive note, some of the questions cover items that most people won't have the slightest clue about. Number of grocery bags in Australia? Who the hell would even have the slightest idea. Historical dates? Either you know them or you don't know them.
It's also the type of things most people don't estimate. People estimate distances, dates that are personal to them, people's ages. Not the amount of material a 747 can hold.
A fine quiz, but I hope he throws out his non-UK results by IP before he uses the data. For many of those topics, my poor American brain had no basis for an estimate and knew it.
The data could be improved by adding the a "no-confidence" checkbox to each question in addition to demanding a numeric answer. With this, he could compare whether people's estimates were better or worse where they thought they knew the answer. This would make a nice complement to measuring raw estimating power.
"We reject as false the choice between our safety and our ideals." --The American President (20.1.2009)
If you're need quick karma, do the following:
1. Post only to new discussions - those with less than 30 comments.
2. Do not reply to main story - instead reply to the first highly modded post.
3. Quote lots of facts or say something political (but keep it loosely on topic and don't use inflammatory statements or you'll get modded a troll).
4. Make your posts long. Long posts are always "Interesting". It's axiomatic.
This will probably get modded Offtopic but since I've got karma to burn and I know how to get it back - I don't think I really care.
I've made up my mind and now I've got to lie in it.
To be sure, some of the numbers requested are not known exactly. But were the error ranges stated in the results any part of the scoring?
It appeared that the quiz wished us to give an estimate and then state a range of error corresponding to our certainty in our result. Did the quiz instead wish us to state a range of error corresponding to how well we thought humanity can measure the particular number?
"We reject as false the choice between our safety and our ideals." --The American President (20.1.2009)
86.5% of all estimates are made up on the spot by an idiot.
Education is the silver bullet.
He has no clue what "estimate" means. He wants you to estimate fixed dates such the year Harold II became King of England. And estimate obscure measured quanta such as the distance between the earth and the moon. The few real categories for estimations are ballpark-pulled-out-of-the-ass number like how many shopping bags are used anually by Australians, and in such cases, his "factual" numbers are so wildly off as to be rediculous. And then after being called on it, admits that he uses basically random numbers and made up equations, and then performs them incorrectly. Then there are the "estimates" which are really biases numbers pulled out of someone else's hat, created to justify personal motivations, using loaded, unquantifiable terms, such as how many british are "functionally" illiterate. Crap. No, shit. His political survey (I quit halfway through) is so loaded as to be even more rEdiculous.
Completely wrong. There are different scales available for dealing with different kinds of ignorance. I tried very hard to learn as little as possible about British royal succession with great success, spoiled only by the fabuluous movie "Henry V". Despite my highly cultivated ignorance, I'd have to be a complete moron not to know that there wasn't much of a British succession in the dark ages, and going back further in time there were a lot of Romans milling about, a lot of bridges and aqueducts, and a distinct shortage of royal castles in London.
Likewise, there weren't many presidents in America (of European descent) prior to 1492. There are always scales of knowledge available for a casting a wider net.
If you want a question worth complaining about: how many joules/kilogram are available from the isomeric decay of Hafnium 2m?
Einstein provided an upper bound, but it's very difficult to apply to this problem.
How come there is no Googol? No GOOG for you!
Simpy
There have been a lot of psychological studies on this phenomena of estimating. Rather, it falls under the broad categories of Judgement and Decision-Making studies. For instance, try this example from a study (Tversky, Kahneman 1974):
Quickly estimate in less than 5 seconds the answer to this multiplication problem:
8 x 7 x 6 x 5 x 4 x 3 x 2 x 1
When this question was asked of a different group of people only in reverse (ie. 1 x 2 x 3 x 4 x 5 x 6 x 7 x 8), people estimated significantly lower than the first group did. For the first group the median estimate was 2250. For the second, the median estimate was only 512!! (The actual answer is 40320 if you are wondering)
The explanation for this is what is called a Framing Effect, which basically means that the way in which the question is asked (or the answers are presented) influences how we respond.
Some other common effects...
-People tend to be overconfident in their responses, which leads us to make poor decisions. ("I'm 80% sure this is correct.")
-Another is Illusory Correlation in which our expectations keep us from judging events and people objectively. (for example, We assume that tall people are good at basketball.)
-We tend to not instinctively believe in statistics... (ie, if we flip a coin 9 times and it comes up Heads, we tend to assume the probability for the next toss being Tails as being more than 50%) Lotteries work this way too, because we overestimate our chances of winning.
-And finally, we show a hindsight bias; that things make perfect sense after the fact.
A good textbook on these topics is Sternberg's "Coginitive Pyschology"
The sending of this message pretty much inconveniences everyone involved.
First - Somebody prolly knows the details on this - but I'd heard a story that Enrico Fermi used to do a radio show where people would try and trip him up on questions of estimation - like how many piano tuners are there in Brooklyn or how many ears of corn in Iowa - and he would do it just with reasonable assumptions in-his-head calcs - and if he hit within 10% either side he wins - the point was they had to stop the program because nobody could stump him. He also used some little pieces of paper and a couple of lines in the desert sand to estimate the yield of the Trinity fusion bomb and hit that within 10%...
The other is that bicycle computers now have a "pace arrow" (Avocet) or "speed control" or some such indicator that tells you when you're above or below the average speed for your ride... Can a better mathematician than me confirm a suspicion - that the rider will want to spend as much time 'above' as possible - but that will raise the average - won't you basically spend half your ride above the average and half below - in other words, you can't always be above the average - unless you steadily increase throughout the ride?
"Win treats sysadmins better than users. Mac treats users better than sysadmins. Linux treats everyone like sysadmins."
At how the quiz was scored. The ranges seem to effectively be the "vote of no confidence" you are requesting, so that if you know you don't know something, you specify a very broad range. I scored very, very low, but had only one answer fall outside the range I estimated.
The quiz is more of a straight "how close can you guess" than it is "how aware are you of what you know," which is more what I expected. My results indicate no accuracy whatsoever, but a very thorough understanding of where the limits of my knowledge are and how big my margin of error will be.
So, I suck at estimating, but at least I'm aware of it.
My buest guess is that the claim is bullshit. Anyway here is an enlightened review
http://www.aaronsw.com/weblog/001315
...estimate various numeric values which they may or may not have knowledge of...
Strangely I find my estimates are much more accurate when I have fore knowledge. Either I've discovered something truely revolutionary and new that the "UK blogger" did not know, or this just means the whole quiz/survey is about as scientifically valid as a women's magazine love survey, or a mens magazine article.
Dear playboy/penthouse,
I never thought it would happen to me, but...
These posts express my own personal views, not those of my employer
"year of birth of Jesus Christ"
Hm. Hard to estimate a "fact" like that.
"And the meaning of words; when they cease to function; when will it start worrying you?"
funny !
Should have said +4 +-1 Funny
You can't handle the truth.
... or is it ¼ empty? Na, it's ½ empty.
Here are a couple of estimation problems that can make decent bar bets:
1) Imagine that you go outside on a clear moonlit night, cover one eye, and hold up a quarter so it appears to cover the moon. Then you move it in or out until it JUST covers the moon. Estimate the distance from the quarter to your eye.
2) Estimate the weight of a six-foot ball of cork.
rj
>You must not have gone to college then. ...and *you* skipped your English classes?
fare better
gewg_
My estimates find that part one is entirely too long a read on too dry a subject for my short attention span.
You need a FREE iPod Nano
Jump off your bike mid-ride, wander into the bush and pinch a couple of loaves. Then you can ride above your average speed all the way home.
Your 10% number boggles the mind. More likely the challenge was order of magnitude (factor of ten). Generally estimating within 20% is possible if you know mostly the right parameters and you estimate the arithmetic results.
Imagine if he could nail 10% all of the time. NASA would be on the phone asking him "for a chunk of foam travelling at 779 ft/s that impacts the wing of a shuttle on launch, how heavy would the foam have to be to cause lethal structural damage?"
Supercomputers can't answer these questions to within ten percent.
The only exception would have to be Sturgeon's law: 90% of everything (e.g. slashdot posts) is junk. Never fails in my experience.
That's my final answer.
I'm sometimes fairly accurate at predicting and estimating things, but I do have to have some prior experience or foreknowledge. Many of the questions were about UK history, geography, and politics, which brought my accuracy rating down considerably. I got 97 points out of 310, so I got a 31% accuracy rating. I demand cultural equality!
On vit, on code et puis on meurt.
> You must not have gone to college then.
You must not have gone to Ivy League then. C's at most of 'em are rare as hen's teeth, and lower grades often simply don't exist - anything lower, and it's as if the student had never taken the class.
> you *should* fair better
One can fare fairly, but cannot fair farely.
...especially if they don't understand where the joke is coming from, to begin with.
(Yeah, yeah, writing sentences (or clauses) that have prepositions which the sentence ends with is considered incorrect, but it sounds more natural--with the exception of this sentence.)
Even in my physics classes, where the grade is said to be curved, I heard that scores around mean of the whole class correspond to B-, and that you need to be only 1 standard deviation higher than the mean to get A--hardly the standard to be expected from cold, hard statistics.
I can't complain, though--I would have gotten lots of B's and B-'s, instead of 4.0's that way.
Maybe they could change the descriptions to:
A: Understands half (or more, but rarely) the materials taught in the class perfectly,
B: Has barely enough basics to continue to higher level classes, but is strongly discouraged.
C: The University requires that I give out only so many D's and F's.
D: I would have given F, but if I give one more, I will have to teach summer school.
F: Have I seen you in the class?
But then, in America, we put boosting kids' self-esteem above all else, don't we?
I'm pretty good at knowing what time it is, and estimating Interstate driving.
I'm also living proof that this skill has no bearing whatsoever on estimating project time...
My God, it's Full of Source!
OUTSIDE_IP=$(dig +short my.ip @outsideip.net)
Thanks! That is, as far as I know, the first time that anyone from /. has followed the link. I will forward your comments to the editor. He will be very pleased to hear we have a following, even a following of one, in the US. Maybe you'd like to contact him yourself: godsrudewireless at hotmail dot com
Download! Print out! Redistribute!
evil math within Nature's Cubic Creation!