Dwight Drane Posted December 22, 2006 Posted December 22, 2006 Sick already? Prepare to get even worse! 1) There's a regression toward the mean thread. 2) The thread's 19 pages long. 3) The thread remained on track (more or less) for all 19 pages. 4) That thread is actually a continuation of a larger regression toward the mean debate that consumed at least 50 pages. 5) The debate was about whether people who obtain extreme scores on imperfect tests will tend to score somewhat closer to the population's mean upon being retested. 6) I eventually found quotes from Stanford, Berkeley, the University of Chicago, the EPA, the University of Washington, Ohio State, and other sources which stated that those who obtain extreme scores on imperfect tests tend to score closer to the population mean upon being retested. You'd think those quotes would be enough to close the mouths of those who'd disagreed with me. But two of my opponents have proven especially stubborn. 874731[/snapback] HIJACK! It isn't a surprise......a more intelligent person should be able to identify a flaw in a test quicker than a person with average intelligence, thus being able to exploit said flaw. Or in football terms....we run the same defense against New England and Miami. Billecheck and Brady pick us apart and win by close to 30.....Mularkey and Saban are still scratching their a$$es after failing to score a point.
Orton's Arm Posted December 22, 2006 Posted December 22, 2006 HIJACK! It isn't a surprise......a more intelligent person should be able to identify a flaw in a test quicker than a person with average intelligence, thus being able to exploit said flaw. Or in football terms....we run the same defense against New England and Miami. Billecheck and Brady pick us apart and win by close to 30.....Mularkey and Saban are still scratching their a$$es after failing to score a point. 875005[/snapback] While you may or may not be right, that's not what we've been arguing about. The phenomenon in question is described here. But it would be really, really pathetic if, 15 weeks into the season, a playoff scenario thread got hijacked by regression toward the mean. So I now return you to your regularly scheduled playoff scenario thread. Go Bills! Go Dolphins! Go Patriots!
Dwight Drane Posted December 22, 2006 Posted December 22, 2006 While you may or may not be right, that's not what we've been arguing about. The phenomenon in question is described here. But it would be really, really pathetic if, 15 weeks into the season, a playoff scenario thread got hijacked by regression toward the mean. So I now return you to your regularly scheduled playoff scenario thread. Go Bills! Go Dolphins! Go Patriots! 875023[/snapback] That's a pretty meaningless phenomenon to me. Below average scores in the 200's are pretty much random guessing....scores in the 700's are pretty much educated guessing. I understand the raw score may be higher than expected, but the top 2% of test takers have to be expected to take better advantage of an easy test than the bottom 2%. In horse racing we translate specific race times and distances into guided numbers called Beyers or Ragozins to get rid of the "luck" involved. A crappy horse can run faster than a better horse during a different race, yet the better horse will more than likely get rewarded with a better number due to track conditions or events that happen during the race. Back to football.....I think Willis, Roscoe and Peters should start a rap group called "Regression Toward the Mean".
bobblehead Posted December 22, 2006 Posted December 22, 2006 The smarter one will not give a crap about the re-test thinking he/she will ace it again. The dumber one will want to try harder, and will probably be thinking about what he/she missed. How does this encompass 50+ pages of internet posting? On better thought, please don't answer this. I like girls.
Orton's Arm Posted December 22, 2006 Posted December 22, 2006 That's a pretty meaningless phenomenon to me. Below average scores in the 200's are pretty much random guessing....scores in the 700's are pretty much educated guessing. I understand the raw score may be higher than expected, but the top 2% of test takers have to be expected to take better advantage of an easy test than the bottom 2%. In horse racing we translate specific race times and distances into guided numbers called Beyers or Ragozins to get rid of the "luck" involved. A crappy horse can run faster than a better horse during a different race, yet the better horse will more than likely get rewarded with a better number due to track conditions or events that happen during the race. Back to football.....I think Willis, Roscoe and Peters should start a rap group called "Regression Toward the Mean". 875136[/snapback] There's more to it than that. Suppose someone was to flip a coin 100 times. You have a group of people trying to predict the outcome of that coin flip. Let's say the most accurate person in the group was able to predict it successfully 65% of the time. This person is now asked to predict the outcome of another 100 coin flips. Odds are this person will only succeed 50% of the time. That extra 15% of success was due entirely to luck; and that luck is expected to disappear when the person gets retested. Now consider something that's based on something innate--such as height. Height measurements aren't expected to change from one trial to the next. Suppose you're dealing with something that's half innate, and half luck. You take the people who had above-average scores. The typical person who had an above-average score obtained half of his or her success to innate ability, and the other half was through luck. When these people are retested, the good luck is expected to go away, but the innate stuff is expected to remain. So they're expected to move halfway toward the population's mean. To, um, relate this to sports, consider a group of highly successful rookies. In selecting that group, you selected players who (on average) were disproportionately lucky. The lucky ones should expect that luck to disappear in their second years, leading to the so-called "sophomore jinx."
Dwight Drane Posted December 22, 2006 Posted December 22, 2006 There's more to it than that. Suppose someone was to flip a coin 100 times. You have a group of people trying to predict the outcome of that coin flip. Let's say the most accurate person in the group was able to predict it successfully 65% of the time. This person is now asked to predict the outcome of another 100 coin flips. Odds are this person will only succeed 50% of the time. That extra 15% of success was due entirely to luck; and that luck is expected to disappear when the person gets retested. Now consider something that's based on something innate--such as height. Height measurements aren't expected to change from one trial to the next. Suppose you're dealing with something that's half innate, and half luck. You take the people who had above-average scores. The typical person who had an above-average score obtained half of his or her success to innate ability, and the other half was through luck. When these people are retested, the good luck is expected to go away, but the innate stuff is expected to remain. So they're expected to move halfway toward the population's mean. To, um, relate this to sports, consider a group of highly successful rookies. In selecting that group, you selected players who (on average) were disproportionately lucky. The lucky ones should expect that luck to disappear in their second years, leading to the so-called "sophomore jinx." 875197[/snapback] I understand the concept, but I disagree on the SAT as being an example. There is little luck involved to those who are in the top 2%. On a show like Jeopardy where there are thousands of categories to choose from...then I understand the theory and feel it is applicable. You never know when Cliff Clavin is going to get his dream show. The theory is more applicable to shorting the stock market during big runs, or drafting LT over Larry Johnson in a fantasy draft this year, as I did.
ezbills Posted December 23, 2006 Author Posted December 23, 2006 Please tell me that there's not actually a regression toward the mean thread... 873680[/snapback] I guess I stepped into the crossfire on that one. Maybe that's why college and graduate school applications often have an essay question like "Do you think your [sAT, LSAT, etc.] score accurately reflects your academic abilities? Why?" That seems like a dumb question to me because the higher your score was, the more accurately it reflects your abilities (in your own opinion). Someone who scores low and then says the test reflects his abilities is asking to be rejected! By the way, here's my two cents on why I'm rooting for the Bengals to beat Denver: http://www.stadiumwall.com/index.php?showt...47entry875547
Orton's Arm Posted December 23, 2006 Posted December 23, 2006 I guess I stepped into the crossfire on that one. Maybe that's why college and graduate school applications often have an essay question like "Do you think your [sAT, LSAT, etc.] score accurately reflects your academic abilities? Why?" That seems like a dumb question to me because the higher your score was, the more accurately it reflects your abilities (in your own opinion). Someone who scores low and then says the test reflects his abilities is asking to be rejected! By the way, here's my two cents on why I'm rooting for the Bengals to beat Denver: http://www.stadiumwall.com/index.php?showt...47entry875547 875551[/snapback] The regression toward the mean thread is a cancer that nearly conquered the PPP board, and seems to be spreading onto the main board. Hopefully future debate will remain confined to the regression toward the mean thread. (BTW, that thread's now at 21 pages.) In any case, your explanation as to which team to root for in the Denver/Bengals game was an excellent one. While I don't have complete confidence in the Dolphins' ability to beat the Jets, I think a Dolphins win is more likely than some other scenarios might be. So I'll still be rooting for Denver. Not that it matters a whole lot--it's not like the Broncos are going to read this thread, see there's one extra guy rooting for them, and decide to play that much harder.
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