Re: Marijuana

2001-06-22 Thread Eamon
Paul Jones <[EMAIL PROTECTED]> wrote in message news:<[EMAIL PROTECTED]>... > There was some research recently linking heart attacks with > Marijuana smoking. > > I'm trying to work out the correlation and, most > importantly, its statistical significance. > > In essence the problem comes down

Re: Marijuana

2001-06-22 Thread Steve Leibel
In article <[EMAIL PROTECTED]>, [EMAIL PROTECTED] (Eamon) wrote: > (c) Reduced motor co-ordination, e.g. when driving a car > Numerous studies have shown that marijuana actually improves driving ability. It makes people more attentive and less aggressive. You could look it up. ==

Re: Marijuana

2001-06-22 Thread Rich Ulrich
On Fri, 22 Jun 2001 18:45:52 GMT, Steve Leibel <[EMAIL PROTECTED]> wrote: > In article <[EMAIL PROTECTED]>, > [EMAIL PROTECTED] (Eamon) wrote: > > > (c) Reduced motor co-ordination, e.g. when driving a car > > > > Numerous studies have shown that marijuana actually improves driving > ability

Re: Normality in Factor Analysis

2001-06-22 Thread Robert Ehrlich
Calculation of eigenvalues and eigenvalues requires no assumption. However evaluation of the results IMHO implicitly assumes at least a unimodal distribution and reasonably homogeneous variance for the same reasons as ANOVA or regression. So think of th consequencesof calculating means and varian

Re: trimming data

2001-06-22 Thread Timothy R. Johnson
"dennis roberts" <[EMAIL PROTECTED]> wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... ... > keep in mind that if the data set is symmetrical ... then, trimming really > accomplishes nothing ... when it comes to the mean ... even if there are > extreme values ... This isn't quite co

Re: Marijuana

2001-06-22 Thread Steve Leibel
In article <[EMAIL PROTECTED]>, Rich Ulrich <[EMAIL PROTECTED]> wrote: > On Fri, 22 Jun 2001 18:45:52 GMT, Steve Leibel <[EMAIL PROTECTED]> > wrote: > > > In article <[EMAIL PROTECTED]>, > > [EMAIL PROTECTED] (Eamon) wrote: > > > > > (c) Reduced motor co-ordination, e.g. when driving a car >

probability that Xi >= X1...Xn

2001-06-22 Thread Fabio Ulisse Pardi
Can anybody give me a hint about this problem? Let the random variables X1,...,Xn be independent and let M be the index of the maximum among them (i.e. M=i implies Xi >= X1,...,Xn). We want to find nice formulas that calculate the distribution of M from the distributions of X1...Xn, that we supp

Re: Normality in Factor Analysis

2001-06-22 Thread Herman Rubin
In article <[EMAIL PROTECTED]>, Robert Ehrlich <[EMAIL PROTECTED]> wrote: >Calculation of eigenvalues and eigenvalues requires no assumption. >However evaluation of the results IMHO implicitly assumes at least a >unimodal distribution and reasonably homogeneous variance for the same >reasons as A

Re: Marijuana

2001-06-22 Thread David C. Ullrich
On Thu, 21 Jun 2001 21:14:44 -0700, Chas F Brown <[EMAIL PROTECTED]> wrote: > > >"David C. Ullrich" wrote: >> >> On Fri, 15 Jun 2001 15:23:03 +0100, Paul Jones >> <[EMAIL PROTECTED]> wrote: >> >> >"David C. Ullrich" wrote: >> >> >> >> But analyzing it this way simply makes no sense. Those >> >>

Re: calculation of an effect size with medians

2001-06-22 Thread Konrad Halupka
Marc wrote: > > As a part of a report > I have to perform a meta-analysis of > some clinical trials. > These trials report the median effect in the > treatment group and the median effect in the control group > (days of hospitalization). P-values from Mann-Whitney U-Tests > are reported and the n