Re: Regression to the mean,Barry Bonds HRs

2001-09-23 Thread Rich Ulrich
On Tue, 18 Sep 2001 21:15:25 +0200, Robert Chung [EMAIL PROTECTED] wrote: [ snip, some of mine, and his comments] ... My main point was and still is that the Slate author used RTM in a sloppy way. That's what I meant by cavalier. I never read the Slate article

Re: Regression to the mean,Barry Bonds HRs

2001-09-23 Thread EugeneGall
Robert Chung wrote Snip Yike, Rich. Are you still sore that Bonds left the Pirates? Go back and check the entire thread. This thing started because on July 13, Eugene Gall quoted an article in Slate that invoked regression to the mean to prove that Bonds wouldn't hit 70. I did post the original

Re: Regression to the mean,Barry Bonds HRs

2001-09-18 Thread Rich Ulrich
the cavalier way that people toss around the phrase, regression to the mean, as if it were an immutable law that trumped all other differences in conditions. You know, I have never seen that. To the best I recollect, I have never seen people toss around regression to the mean in a cavalier way

Re: Regression to the mean,Barry Bonds HRs

2001-09-18 Thread Robert Chung
, Eugene Gall quoted an article in Slate that invoked regression to the mean to prove that Bonds wouldn't hit 70. I only entered the thread a month later when you said that Bonds must be on steroids, and pointed out that looking at Bonds' past history wasn't much of a guide because he was hitting

Re: Regression to the mean,Barry Bonds HRs

2001-09-17 Thread Robert Chung
Candlestick was, sorta like the short right front porch at Yankee stadium. Matter of fact, if Hank Aaron had played half his games in Candlestick while Willie Mays had played half his in Atlanta... Discussions about regression to the mean (and comments that Bonds has never before hit 50) might

Re: Regression to the mean,Barry Bonds HRs

2001-09-17 Thread Dennis Roberts
My main point was not about baseball or Bonds. It was about the cavalier way that people toss around the phrase, regression to the mean, as if it were an immutable law that trumped all other differences in conditions. --Robert Chung right ... reg. to the mean is not a cause of anything

Re: Regression to the mean,Barry Bonds HRs

2001-09-16 Thread Rich Ulrich
the short right front porch at Yankee stadium. Matter of fact, if Hank Aaron had played half his games in Candlestick while Willie Mays had played half his in Atlanta... Discussions about regression to the mean (and comments that Bonds has never before hit 50) might be more relevant if all other

Re: Regression to the mean,Barry Bonds HRs

2001-08-28 Thread Dennis Roberts
SO, when bonds hits 73 ... what will people say vis a vis regression to the mean? At 11:40 PM 8/27/01 -0400, Stan Brown wrote: Rich Ulrich [EMAIL PROTECTED] wrote in sci.stat.edu: This was a topic a month ago. Just to bring things up to date

Re: Regression to the mean,Barry Bonds HRs

2001-08-28 Thread Robert Chung
Rich Ulrich wrote: On 28 Aug 2001 06:38:49 -0700, [EMAIL PROTECTED] (Dennis Roberts) wrote: SO, when bonds hits 73 ... what will people say vis a vis regression to the mean? ... steroids ... ? (have to guess that for the 56 he already has.) Hmmm. I would have suggested that Pac

Re: Regression to the mean,Barry Bonds HRs

2001-08-27 Thread Rich Ulrich
This was a topic a month ago. Just to bring things up to date Barry Bonds hit 38 homers in the first half of the season (81 games), a record pace. Should we expect his performance to regress to the mean sufficiently that he would not break the season record of 70? BB had never hit 50 in

Re: Regression to the mean,Barry Bonds HRs

2001-08-27 Thread Stan Brown
Rich Ulrich [EMAIL PROTECTED] wrote in sci.stat.edu: This was a topic a month ago. Just to bring things up to date Barry Bonds hit 38 homers in the first half of the season (81 games), a record pace. Should we expect his performance to regress to the mean sufficiently that he would not

Re: Regression to the mean,Barry Bonds HRs

2001-07-23 Thread Rich Ulrich
- I am taking a second try at this question from dmr - On 17 Jul 2001 15:23:29 -0700, [EMAIL PROTECTED] (dennis roberts) wrote: At 04:08 PM 7/17/01 -0400, Rich Ulrich wrote: But, so far as I have heard, the league MEANS stay the same. The SDs are the same. There is no preference, that I

Re: Regression to the mean,Barry Bonds HRs

2001-07-18 Thread Rich Ulrich
On 17 Jul 2001 15:23:29 -0700, [EMAIL PROTECTED] (dennis roberts) wrote: At 04:08 PM 7/17/01 -0400, Rich Ulrich wrote: But, so far as I have heard, the league MEANS stay the same. The SDs are the same. There is no preference, that I have ever heard, for records to be set by half-season,

Re: Regression to the mean,Barry Bonds HRs

2001-07-17 Thread Rich Ulrich
On 16 Jul 2001 09:31:08 -0700, [EMAIL PROTECTED] (dennis roberts) wrote: [ snip, RTTM is about 'relative' values ... ] the issue that has to be raised with respect to the baseball example is ... are the two halves PARALLEL HALVES? ... like, parallel tests given at essentially the same

Re: Regression to the mean,Barry Bonds HRs

2001-07-17 Thread dennis roberts
At 04:08 PM 7/17/01 -0400, Rich Ulrich wrote: But, so far as I have heard, the league MEANS stay the same. The SDs are the same. There is no preference, that I have ever heard, for records to be set by half-season, early or late, team or individual. My guess is that association between talent

Re: Regression to the mean,Barry Bonds HRs

2001-07-16 Thread dennis roberts
regression to the mean has NOTHING to do with raw numbers ... it ONLY has to do with relative location withIN a distribution example: i give a course final exam the first day ... and get scores (on 100 item test) from 10 to 40 ... and an alternate form of the final on the last day ... and get

Re: Regression to the mean,Barry Bonds HRs

2001-07-16 Thread EugeneGall
that regression to the mean doesn't imply a loss in diversity. = Instructions for joining and leaving this list and remarks about the problem of INAPPROPRIATE MESSAGES are available at http://jse.stat.ncsu.edu/ =

Re: Regression to the mean,Barry Bonds HRs

2001-07-16 Thread EugeneGall
Paige Miller wrote: EugeneGall wrote: This hardly PROVES anything. It is more a statement about what has happened in the past. Proves was in the original article. I'm assuming Ellenberg, a mathematics prof, was using 'proves' in a tongue-in-cheek fashion. However, he was serious in

Re: Regression to the mean,Barry Bonds HRs

2001-07-16 Thread Paige Miller
EugeneGall wrote: Jordan Ellenberg, in today's Slate, PROVES that Bonds won't break the HR record because of regression to the mean. The argument is a little sloppy, but there is definitely some RTM involved: If our discussion above is correct, then hitters who lead the major leagues

Re: Regression to the mean,Barry Bonds HRs

2001-07-16 Thread Rich Ulrich
On 14 Jul 2001 00:26:03 GMT, [EMAIL PROTECTED] (EugeneGall) wrote: [ snip, about Bonds and home runs, and Regression to the Mean ] I'd be curious if reduction in the 1st half leaders was comparable to the improvement in the 2nd half leaders. Huh? If you are asking what I think you

Regression to the mean,Barry Bonds HRs

2001-07-13 Thread EugeneGall
Jordan Ellenberg, in today's Slate, PROVES that Bonds won't break the HR record because of regression to the mean. The argument is a little sloppy, but there is definitely some RTM involved: If our discussion above is correct, then hitters who lead the major leagues in home runs at the All

Re: regression to the mean

2001-01-26 Thread J E H Shaw
Dennis, I agree with all your points; I thought the news report was a nice example related to regression to the mean and of attempting to prop up a (nearly certainly true) statement using invalid statistics - note that the report appears to refer to the *current* top bottom 10% and what

Re: regression to the mean

2001-01-26 Thread
In article 94qi92$[EMAIL PROTECTED], [EMAIL PROTECTED] (Herman Rubin) writes: This has nothing to do with regression to the mean. The people in the top 10% and the bottom 10% have changed. I see "regression to the mean" and "the people in the top 10% and the bottom 1

Re: regression to the mean

2001-01-26 Thread Rich Ulrich
... that is ... some % value is that amount that increments their salaries ... snip, other stuff based on this misreading And Dennis quotes the material -- At 05:07 PM 1/25/01 +, wrote: Avid regression-to-the-mean watchers may be interested to know that, according to yesterday's summary

regression to the mean

2001-01-25 Thread
Avid regression-to-the-mean watchers may be interested to know that, according to yesterday's summary of the growing rich-poor divide (on teletext news), the current top 10% of earners have had a higher percentage increase in income over the past x years (for some x that I've forgotten) than

Re: regression to the mean

2001-01-25 Thread dennis roberts
this will be quite high) ... thus, there still will be SOME regression to the mean that is ... if we isolate the top 50 ... and the bottom 50 ... and look at their percentile ranks (or mean z scores) from this year to next ... you will still see that the lower 50 have relatively higher percentile ranks than

Re: regression to the mean

2001-01-25 Thread Herman Rubin
In article 94pmgo$rn7$[EMAIL PROTECTED], [EMAIL PROTECTED] wrote: Avid regression-to-the-mean watchers may be interested to know that, according to yesterday's summary of the growing rich-poor divide (on teletext news), the current top 10% of earners have had a higher percentage increase

Re: change scores (and more on regression to the mean)

2001-01-24 Thread Will Hopkins
My response is about regression to the mean generally, which got done over a little over a week ago. It occurred to me recently that you could reduce the regression-to-the-mean effect by using the subjects' least-squares means to divide them (the subjects) up into quantiles for separate

Re: regression to the mean

2001-01-19 Thread Robert Chung
e two sets of "test" measures ... would qualify for being a context in which to illustrate RTM? Not at all. If there's a perfect r you _won't_ see regression to the mean! What it means is that not everything which expands or compresses the ends of a distribution is RTM. My understa

Re: regression to the mean

2001-01-17 Thread Bob Wheeler
I've heard this before -- probably read it in stat books. It isn't true. Galton worried over the problem until he understood the statistical mechanism. He even designed a device (the Quincunx) to demonstrate how it works. Steve Stigler has a section on it in his new book. Thus Galton found

Re: regression to the mean

2001-01-17 Thread dennis roberts
31 26 2142 27 2032 28 2024 29 1439 30 1143 if you are thinking about regression to the mean in the typical way ... how come this "regression reversal" s

Re: regression to the mean

2001-01-17 Thread Elliot Cramer
On Wed, 17 Jan 2001, Bob Wheeler wrote: I've heard this before -- probably read it in stat books. It isn't true. Galton worried over the problem until he understood the statistical mechanism. you may abe right; that's why I said apparrently

Re: regression to the mean

2001-01-17 Thread Elliot Cramer
J. Williams [EMAIL PROTECTED] wrote: Would this not : be the same as the offspring of either the very tall or the very short : among us moving toward an arithmetic average? Is it inconceivable : that a pair of dullards could produce a Beethoven or a Fermi for : example? Frankly, I believe old

Re: regression to the mean

2001-01-17 Thread dennis roberts
here are some of the actual reported galton data ... scatterplots between fathers' and sons' heights ... interesting tidbit about these data ... clearly, some fathers sired not only sons ... but also daughters ... S ... for the case of daughters ... the value that was imputed was a

Re: regression to the mean

2001-01-17 Thread dennis roberts
you could clarify what is and what is not ... RTM? Thus it hides the effect of regression to the mean; however, we may guess that the size of the improvement is somewhat reduced. -Robert Dawson = Instructions for joining a

Re: regression to the mean

2001-01-17 Thread Robert J. MacG. Dawson
Paul R Swank forwarded Dennis' scattterplot: - * post - * * - * - 2 * 80+ * 2 * - 2 * * * - * * * - * * - * * 60+ - * * - * * * - - * 40+ * - - +-+-+-+-+-+--pre 10.0 15.0 20.0 25.0 30.0 35.0 Aha! So

Re: regression to the mean

2001-01-17 Thread Paul R Swank
divide at the midpoint of the pretest to form two equal size groups. At 01:37 PM 1/17/01 -0500, you wrote: >At 12:28 PM 1/17/01 -0600, Paul R Swank wrote: >>But if you group the subjects on the basis of their pretest scores, the >>lowest group gains 23.1 points while the highest group only gains