Re: Applied analysis question

On 28 Feb 2002 07:37:16 -0800, [EMAIL PROTECTED] (Brad Anderson) wrote: > Rich Ulrich <[EMAIL PROTECTED]> wrote in message >news:<[EMAIL PROTECTED]>... > > On 27 Feb 2002 11:59:53 -0800, [EMAIL PROTECTED] (Brad Anderson) > > wrote: BA > > > > > > I have a continuous response variable that range

Re: Applied analysis question

s > the data [ snip, rest] Looks to me like it might be reasonable to re-sort and re-score the speed as reciprocal, "questions per hour" -- instead of the original, hours per question. That emphasizes something you (perhaps) omitted: some tests at the end were incomplete. Also, Q/H

Re: Splus or R

Anonymous God-fearer <[EMAIL PROTECTED]> wrote: > Does anyone know how to generate a correlation matrix given a covariance > matrix in Splus? > Or could you give the details of how to do it in another language? corr[i,j] = cov[i,j]/sqrt(cov[i,i]*cov[j,j]) ===

Re: help on factor analysis/non-normality

to amplifiy a bit, the interpretability of regression tends to go down as the assumptions of normality and homogeneous variance are markedly different from reality. You can still go through the calcualtions but the interpretation of results gets tricky. Factor analysis is a sort of regression an

Re: AIC

SR Millis wrote in message <[EMAIL PROTECTED]>... >What is the correct pronunciation for "Akaike" as in AIC? > >Thanks, >SR Millis (rhymes with "bacillus") > > In Japanese, all letters are pronounced. Try: Aka-ee-ke Now try pronouncing Toyota! `y` is always a consonant in Japanese, so it should

Re: Robust regression

If, for example, normality assumption holds then by doing robust regression instead of OLS you lose efficiency. So, it's not the same result after all. But you can do both, compare and decide. If robust regression produces results which are not really different from the OLS then stay with OLS. On

Re: Robust regression

You don't need normality for regression. You may need it for certain optimality properties to hold, but you can apply OLS without normality. On 1 Mar 2002, Alex Yu wrote: > > I know that robust regression can downweight outliers. Should someone > apply robust regression when the data have skewe

Re: Robust regression

On 1 Mar 2002 00:36:01 -0800, [EMAIL PROTECTED] (Alex Yu) wrote: > > I know that robust regression can downweight outliers. Should someone > apply robust regression when the data have skewed distributions but do not > have outliers? Regression assumptions require normality of residuals, but > no

Re: help on factor analysis/non-normality

On 1 Mar 2002 04:51:42 -0800, [EMAIL PROTECTED] (Mobile Survey) wrote: > What do i do if I need to run a factor analysis and have non-normal > distribution for some of the items (indicators)? Does Principal > component analysis require the normality assumption. There is no problem of non-normal

Re: Applied analysis question

[EMAIL PROTECTED] (Eric Bohlman) wrote in message news:... > Rolf Dalin <[EMAIL PROTECTED]> wrote: > > IIRC, your example is exactly the sort of situation for which Tobit > modelling was invented. Considered that (actually estimated a couple of Tobit models and if I use a log transformed or bo

Re: REML for Dummies?

The Enclyclopedia of Biostatistics (Armitage P, Colton T; Wiley, 1999?) has an article on REML. I have not seen the article, but usually their articles well explain statistical concepts to non-statisticians. The Encyclopedia is a resource you might find helpful in general. For more info, see:

Re: Applied analysis question

Rolf Dalin <[EMAIL PROTECTED]> wrote: > Brad Anderson wrote: >> I have a continuous response variable that ranges from 0 to 750. I only >> have 90 observations and 26 are at the lower limit of 0, > What if you treated the information collected by that variable as really > two variables, one ca

Re: detecting outliers in NON normal data ?

But Mahalanobis distance is sensible to swamping and masking so is it really a good measure for outliers? DELOMBA a écrit dans le message ... >What about Hat Matrix ? Mahalanobis distance ? > >Yves > > >"Voltolini" <[EMAIL PROTECTED]> wrote in message >00f301c1be68$13413000$fde9e3c8@oemcomputer..

Re: REML for Dummies?

A good book is Pinheiro, J.C. and Bates., D.M. "mixed models with S and S-Plus", Springer. Kjetil Halvorsen Dr Jonathan Newman wrote: > > I'm trying to find a good introduction to REML (restricted maximum > likelihood). I'm a biologist rather than a statistician. If you have any > suggesti

Re: REML for Dummies?

Dr Jonathan Newman wrote: > > I'm trying to find a good introduction to REML (restricted maximum > likelihood). I'm a biologist rather than a statistician. If you have any > suggestions I'd great appreciate hearing them. Thanks. Lynch & Walsh (1998)? (Genetic Analysis of Quantitative Traits,

Re: Applied analysis question

On 27 Feb 2002 14:14:44 -0800, [EMAIL PROTECTED] (Dennis Roberts) wrote: > At 04:11 PM 2/27/02 -0500, Rich Ulrich wrote: > > >Categorizing the values into a few categories labeled, > >"none, almost none, " is one way to convert your scores. > >If those labels do make sense. > well, if 750

Re: Find PDF of RV with a given mean value

In article <[EMAIL PROTECTED]>, Glen <[EMAIL PROTECTED]> wrote: >"Chia C Chong" <[EMAIL PROTECTED]> wrote in message >news:... >> Hi! >> I have a set of random numbers and if I know their expectation/mean, would >> it be possible to deduce a PDF to describe the distribution of them? >Knowing t

Re: Means of semantic differential scales

At 09:51 AM 2/28/02 -0800, Jay Tanzman wrote: >I partially did this, insofar as I ran Pearson and Spearman correlations >between >several of the scales and, not surprisingly, the two correlation coefficients >and their p-values were similar. < that issue is entirely a separate >one since t

Re: Means of semantic differential scales

> "Simon, Steve, PhD" wrote: > > Jay Tanzman got chewed out by his boss for averaging a 7 point ordinal scale. > Generally it is not a good idea to argue with your boss, but perhaps you might > ask what was the grade point average that he or she received in college. When > you hear the response

Re: Applied analysis question

At 07:37 AM 2/28/02 -0800, Brad Anderson wrote: >I think a lot of folks just run standard analyses or arbitrarily apply >some "normalizing" transformation because that's whats done in their >field. Then report the results without really examining the >underlying distributions. I'm curious how f

Re: Applied analysis question

Rich Ulrich <[EMAIL PROTECTED]> wrote in message news:<[EMAIL PROTECTED]>... > On 27 Feb 2002 11:59:53 -0800, [EMAIL PROTECTED] (Brad Anderson) > wrote: > > > I have a continuous response variable that ranges from 0 to 750. I > > only have 90 observations and 26 are at the lower limit of 0, whi

RE: Means of semantic differential scales

Title: RE: Means of semantic differential scales Jay Tanzman got chewed out by his boss for averaging a 7 point ordinal scale. Generally it is not a good idea to argue with your boss, but perhaps you might ask what was the grade point average that he or she received in college. When you hear

Re: Means of semantic differential scales

On 27 Feb 2002 15:01:24 -0800, [EMAIL PROTECTED] (Dennis Roberts) wrote: >At 01:39 PM 2/27/02 -0600, Jay Warner wrote: > >> > > >> > >Not stressful 1__ 2__ 3__ 4__ 5__ 6__ 7__ Very stressful > >just out of curiosity ... how many consider the above to be an example of a >bipolar scale? > >i don't

Re: Means of semantic differential scales

DMR, I should have read your previous posting more carefully. I have now had coffee. >Not stressful 1__ 2__ 3__ 4__ 5__ 6__ 7__ Very stressful is a question that has an extent response format. The cognitive schema the response format tries to invoke might be reinforced by anchoring with zero f

Re: Means of semantic differential scales

I would consider it a unipolar extent scale. Maybe the visual anchor should be 0 to 6 to aid association with the number line concept. Dennis Roberts wrote: > At 01:39 PM 2/27/02 -0600, Jay Warner wrote: > > > > > > > > >Not stressful 1__ 2__ 3__ 4__ 5__ 6__ 7__ Very stressful > > just out of c

Re: Applied analysis question

Brad Anderson wrote: > I have a continuous response variable that ranges from 0 to 750. I only > have 90 observations and 26 are at the lower limit of 0, What if you treated the information collected by that variable as really two variables, one categorical variable indicating zero or non-zero

Re: Statistics Tool For Classification/Clustering

Good places to start: Optimal feature extractors, that's better than PCA because you whiten your inter class scatter and so put all inter class comparisons on the same level. The good thing is this will also reduce your feature vector dimensionality to c-1 (where c is # classes). PCA will not do

Re: Statistics Tool For Classification/Clustering

Corection typo: Should read 'Whiten intra class scatter' "Mark Harrison" <[EMAIL PROTECTED]> wrote in message news:FIif8.16518$[EMAIL PROTECTED].; > Good places to start: > > Optimal feature extractors, that's better than PCA because you whiten your > inter class scatter and so put all inter clas

Re: Applied analysis question

i thought of a related data situation ...but at the opposite end what if you were interested in the relationship between the time it takes students to take a test AND their test score so, you have maybe 35 students in your 1 hour class that starts at 9AM ... you decide to note (by your watch) t

Re: Applied analysis question

Brad Anderson wrote: > > I have a continuous response variable that ranges from 0 to 750. I > only have 90 observations and 26 are at the lower limit of 0, which is > the modal category. If it's continuous, it can't really have categories (apart from those induced by recording the variable to

Re: Means of semantic differential scales

At 01:39 PM 2/27/02 -0600, Jay Warner wrote: > > > > > >Not stressful 1__ 2__ 3__ 4__ 5__ 6__ 7__ Very stressful just out of curiosity ... how many consider the above to be an example of a bipolar scale? i don't now, if we had an item like: sad happy 1 . 7 THEN the mid point b

Re: Applied analysis question

At 04:11 PM 2/27/02 -0500, Rich Ulrich wrote: >Categorizing the values into a few categories labeled, >"none, almost none, " is one way to convert your scores. >If those labels do make sense. well, if 750 has the same numerical sort of meaning as 0 (unit wise) ... in terms of what is being

Re: Means of semantic differential scales

I am humbled by the insight & background knowledge expressed by Mssrs. Williams and McLean, not to mention the string of others. My lack of academic experince in the subject matter is painfully clear. Now to see if I can find Osgood et al. When I consider how many research projects and social/p

Re: Applied analysis question

On 27 Feb 2002 11:59:53 -0800, [EMAIL PROTECTED] (Brad Anderson) wrote: > I have a continuous response variable that ranges from 0 to 750. I > only have 90 observations and 26 are at the lower limit of 0, which is > the modal category. The mean is about 60 and the median is 3; the > distributio

Re: CRIMCOORD transformation in QUEST

That is either a sloppiness in writing or reliance on the relationship between eigen decomposition and SVD. SSM - square symmetric matrix AM - arbitrary matrix In ED, SSM = Q E Q' In SVD, AM = P D Q' SSM = AM' AM = Q D P' P D Q' = Q D D Q' = Q E Q', if E = D D I haven't checked

Re: detecting outliers in NON normal data ?

What about Hat Matrix ? Mahalanobis distance ? Yves "Voltolini" <[EMAIL PROTECTED]> wrote in message 00f301c1be68$13413000$fde9e3c8@oemcomputer">news:00f301c1be68$13413000$fde9e3c8@oemcomputer... > Hi, > > I would like to know if methods for detecting outliers > using interquartil ranges are in

Re: (È«º¸)ÃÖ°­È«º¸ÇÁ·Î±×·¥!!È«º¸°ÆÁ¤³¡.

This is a multi-part message in MIME format. --=_NextPart_000_0017_01C1BFC6.F446E040 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable O=BA=BB=B8=DE=C0=CF=C0=BA=C1=A4=BA=B8=C5=EB=BD=C5=B8=C1=C0=CC=BF=EB=C3=CB= =C1=F8=B9=D7=C1=A4=BA=B8=BA=B8=C8

Re: Find PDF of RV with a given mean value

"Chia C Chong" <[EMAIL PROTECTED]> wrote in message news:... > Hi! > > I have a set of random numbers and if I know their expectation/mean, would > it be possible to deduce a PDF to describe the distribution of them? Knowing the mean tells you (almost) nothing abo

Re: Means of semantic differential scales

Jay Tanzman wrote: > > Jay Warner wrote: > > > > Jay Tanzman wrote: > > > > > I just got chewed out by my boss for modelling the means of some 7-point > > > semantic differential scales. The scales were part of a written, > > > self-administered questionnaire, and were laid out like this: > >

Re: What is a qualitative ordinal variable?

part 2. Ordinal variables come in two flavors. In purely ordinal data the number of distinct values is pretty much the same as the number of cases. In ordered category variables, there are only a few values that a variable may take, but the intervals are perceived as very different. Interval var

Re: What is a qualitative ordinal variable?

part 1. A lot depends on your discipline. Since the issue of level of measurement rose in the 60's and early 70's there have been different viewpoint. For some qualitative data means textual or pictorial information. For some it means nominal level data. For some it means variables that the meas

Re: Means of semantic differential scales

> > > 2. Perhaps more likely, your boss may have learned > > (wrongly?) that parametric stats should not be done unless scales > > of measurement are at least interval in quality. > > I don't know if his objection was to parametric statistics per se, but he did > object to calculating means on t

Re: What is an outlier ?

and with bivariate data, neither component need be high or low! Jon Cryer At 12:14 PM 2/25/2002 -0700, you wrote: >Of course it can be. An outlier is any value that is not usual for your data >set. >"Voltolini" <[EMAIL PROTECTED]> wrote in message >002f01c1be21$65913d60$0fe9e3c8@oemcomputer">new

Re: Means of semantic differential scales

At 08:18 AM 2/26/02 -0800, Jay Tanzman wrote: > > > > > > Not stressful 1__ 2__ 3__ 4__ 5__ 6__ 7__ Very stressful these contain more information than simply ordinality ... they give you some indication of amount of stress too differentiate this sort of item and response from: rank order your

Re: Means of semantic differential scales

i think we are all missing the main point if you have a number of these items where, your goal (perhaps) is to SUM them together in some way ... where one end represents low amounts of the "thing" presented and the other end represents large amounts of the thing presented ... then ACROSS items

Re: Means of semantic differential scales

Jay Warner wrote: > > Jay Tanzman wrote: > > > I just got chewed out by my boss for modelling the means of some 7-point > > semantic differential scales. The scales were part of a written, > > self-administered questionnaire, and were laid out like this: > > > > Not stressful 1__ 2__ 3__ 4__

Re: Means of semantic differential scales

jim clark wrote: > > Hi > > On Mon, 25 Feb 2002, Jay Tanzman wrote: > > > I just got chewed out by my boss for modelling the means of some 7-point > > semantic differential scales. The scales were part of a written, > > self-administered questionnaire, and were laid out like this: > > > > No

Re: Means of semantic differential scales

"J. Williams" wrote: > > On Mon, 25 Feb 2002 15:17:55 -0800, Jay Tanzman <[EMAIL PROTECTED]> > wrote: > > >I just got chewed out by my boss for modelling the means of some 7-point > >semantic differential scales. The scales were part of a written, > >self-administered questionnaire, and were

Re: detecting outliers in NON normal data ?

In article <00f301c1be68$13413000$fde9e3c8@oemcomputer>, Voltolini <[EMAIL PROTECTED]> wrote: >Hi, >I would like to know if methods for detecting outliers >using interquartil ranges are indicated for data with >NON normal distribution. >The software "Statistica" presents this method: >data point

Re: Cauchy PDF + Parameter Estimate

In article <[EMAIL PROTECTED]>, Glen Barnett <[EMAIL PROTECTED]> wrote: >Herman Rubin wrote: >> In article , >> Chia C Chong <[EMAIL PROTECTED]> wrote: >> >Hi! >> >Does anyone come across some Matlab code to estimate the parameters for the >> >Cauchy PDF?? Or some

Re: STATA Constrained Regression

Have you looked in the manual under "Constraint"? If you still have a problem you should submit your question either to Stata tech support or to the Stata list server (you can join at the Stata web site: http://www.stata.com), rather than to a general newsgroup such as this one. Rich Goldstein

Re: Means of semantic differential scales

Hi On Mon, 25 Feb 2002, Jay Tanzman wrote: > I just got chewed out by my boss for modelling the means of some 7-point > semantic differential scales. The scales were part of a written, > self-administered questionnaire, and were laid out like this: > > Not stressful 1__ 2__ 3__ 4__ 5__ 6__ 7__

Re: Numerical recipes in statistics ???

In sci.stat.edu The Truth <[EMAIL PROTECTED]> wrote: > Glen Barnett <[EMAIL PROTECTED]> wrote in message >news:<[EMAIL PROTECTED]>... >> The Truth wrote: >> > >> > Are there any "Numerical Recipes" like textbook on statistics and probability ? >> > Just wondering.. >> >> What do you mean, a boo

Re: Means of semantic differential scales

of course, to be fair to the first jay .. could be simply that his boss did not like semantic diff. scales ... AND, for none of the reasons the second jay below said ... it would be helpful if the first jay could give us some further info on why his boss was so ticked off ... At 09:39 PM 2/25

Re: Means of semantic differential scales

Jay Tanzman wrote: > I just got chewed out by my boss for modelling the means of some 7-point > semantic differential scales. The scales were part of a written, > self-administered questionnaire, and were laid out like this: > > Not stressful 1__ 2__ 3__ 4__ 5__ 6__ 7__ Very stressful > > So, wh

Re: What is an outlier ?

Voltolini wrote: > > Hi, > > My doubt isan outlier can be a LOW data value in the sample (and not > just the highest) ? > > Several text boks dont make this clear !!! What makes an outlier "an outlier" is your model. If your model accounts for all the observations, you can't really call an

Re: Cauchy PDF + Parameter Estimate

Herman Rubin wrote: > > In article , > Chia C Chong <[EMAIL PROTECTED]> wrote: > >Hi! > > >Does anyone come across some Matlab code to estimate the parameters for the > >Cauchy PDF?? Or some other sources about the method to estimate their > >parameters?? > > What

Re: detecting outliers in NON normal data ?

Voltolini wrote: > > Hi, > > I would like to know if methods for detecting outliers > using interquartil ranges are indicated for data with > NON normal distribution. > > The software "Statistica" presents this method: > data point value > UBV + o.c.*(UBV - LBV) > data point value < LBV - o.c.*

Re: Means of semantic differential scales

On Mon, 25 Feb 2002 15:17:55 -0800, Jay Tanzman <[EMAIL PROTECTED]> wrote: >I just got chewed out by my boss for modelling the means of some 7-point >semantic differential scales. The scales were part of a written, >self-administered questionnaire, and were laid out like this: > >Not stressful 1

Re: What is an outlier ?

of course, if one has control over the data, checking the coding and making sure it is correct is a good thing to do if you do not have control over that, then there may be very little you can do with it and in fact, you may be totally UNaware of an outlier problem i see as a potentially MUCH

Re: Cauchy PDF + Parameter Estimate

In article , Chia C Chong <[EMAIL PROTECTED]> wrote: >Hi! >Does anyone come across some Matlab code to estimate the parameters for the >Cauchy PDF?? Or some other sources about the method to estimate their >parameters?? What is so difficult about maximum likelihood?

Re: What is an outlier ? cont'd

--A59A95727DA65C2AB2F9EBF5 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit That being said, occasions can arise where there are outliers other than from measurement or data entry error. Different disciplines have different approaches. What discipline are yo

Re: What is an outlier ?

Of course it can be. An outlier is any value that is not usual for your data set. "Voltolini" <[EMAIL PROTECTED]> wrote in message 002f01c1be21$65913d60$0fe9e3c8@oemcomputer">news:002f01c1be21$65913d60$0fe9e3c8@oemcomputer... > Hi, > > > My doubt isan outlier can be a LOW data value in the sam

Re: Cauchy PDF + Parameter Estimate

On 25 Feb 2002 07:56:56 -0800, [EMAIL PROTECTED] (kjetil halvorsen) wrote: >It isstraightforward tlo write down the loglikelihood, and then whatever >optimization routine (there must be one in Matlab) will help you! Just be careful when searching, because Cauchy likelihoods are frequently multi-

Re: Question on Conditional PDF

"Glen Barnett" <[EMAIL PROTECTED]> wrote in message a5dev7$8jn$[EMAIL PROTECTED]">news:a5dev7$8jn$[EMAIL PROTECTED]... > > Chia C Chong <[EMAIL PROTECTED]> wrote in message > a5d38d$63e$[EMAIL PROTECTED]">news:a5d38d$63e$[EMAIL PROTECTED]... > > > > > > "Glen" <[EMAIL PROTECTED]> wrote in message

Re: REQ: Appendix A. of Radford Neal thesis: "Bayesian Learning for

Mark wrote: > > Hi, > > I'm CS student interested in Radford Neal thesis called "Bayesian > Learning for Neural Networks". I know that some years ago this thesis > was available for download from author's site, but nowadays there > isn't possible. I have searched it on Intenet so I have not kno

Re: Question on Conditional PDF

> > > Do you want to make any assumptions about the form of the conditional, > > > or the joint, or any of the marginals? > > > > Well, the X & Y are dependent and hence there are being descibed by a joint > > PDF. > > Can you at least indicate whether any of them are restricted to be positive?

Re: Cauchy PDF + Parameter Estimate

It isstraightforward tlo write down the loglikelihood, and then whatever optimization routine (there must be one in Matlab) will help you! Kjetil Halvorsen Chia C Chong wrote: > > Hi! > > Does anyone come across some Matlab code to estimate the parameters for the > Cauchy PDF?? Or some other s

Re: regression of non-normal data ?

John Ziker wrote: > This research deals with the classical anthropological question of > food sharing among hunters and gatherers. There are a number of > hypotheses being discussed within the field. This study is relevant > for two models, namely kinship cooperation and reciprocity. The > kinshi

Re: Question on Conditional PDF

Chia C Chong <[EMAIL PROTECTED]> wrote in message a5d38d$63e$[EMAIL PROTECTED]">news:a5d38d$63e$[EMAIL PROTECTED]... > > > "Glen" <[EMAIL PROTECTED]> wrote in message > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > Do you want to make any assumptions about the form of the conditional, > > or t

Re: odds vs probabilities

MAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Saturday, February 23, 2002 9:49 AM Subject: Re: odds vs probabilities > probabilities. I know that probs have a problem in that they don't > make multiplicative sense:

Re: Question on Conditional PDF

"Glen" <[EMAIL PROTECTED]> wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > [EMAIL PROTECTED] (Chia C Chong) wrote in message news:<[EMAIL PROTECTED]>... > > Helloo.. > > > > I have 1000 samples 3 RVs (say X, Y and Z) drawn from a series of > > experiments. My intention is to find

Re: Question on Conditional PDF

[EMAIL PROTECTED] (Chia C Chong) wrote in message news:<[EMAIL PROTECTED]>... > Helloo.. > > I have 1000 samples 3 RVs (say X, Y and Z) drawn from a series of > experiments. My intention is to find the PDF of Z condition on X and Y > i.e. f(Z|X,Y). I am not sure what is the proper way of doing i

Re: Question on Conditional PDF

if you don't want to make to many assumptions then you can try nonparametric estimation (estimate f(X,Y,Z) and f(X,Y) by kernel methods). Check out books on nonparametric methods ("Nonparametric Econometrics" by Pagan, for example, or a book by Silverman(?)). On 24 Feb 2002, Chia C Chong wrote:

Re: Appendix A. of Radford Neal thesis: "Bayesian Learning for Neural Networks"

Mark <[EMAIL PROTECTED]> wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > Hi, > > I'm CS student interested in Radford Neal thesis called "Bayesian > Learning for Neural Networks". I know that some years ago this thesis > was available for download from author's site, but nowadays

Re: REQ: Appendix A. of Radford Neal thesis: "Bayesian Learning for Neural Networks"

On Fri, 22 Feb 2002 18:00:16 +0100, Mark <[EMAIL PROTECTED]> wrote: > Hi, > > I'm CS student interested in Radford Neal thesis called "Bayesian > Learning for Neural Networks". I know that some years ago this thesis > was available for download from author's site, but nowadays there > isn't pos

Re: odds vs probabilities

On 23 Feb 2002 06:49:58 -0800, [EMAIL PROTECTED] (Brad Branford) wrote: > hi, > > thanks. sorry if I posed the question poorly. actually, what I'm > looking for is an intuitive understanding of when to use odds and when > probabilities. I know that probs have a problem in that they don't > make

Re: Probabilities

Zachary Agatstein wrote: > > Can you help me solve this problem: > > There are 8 baskets and 4 apples. Thrown at random, 3 of the 4 apples > can go to any basket. The 4th apple, however, can only be thrown into > baskets 1 through 4. What is the probability that there is no more than > one

Re: What is an experiment ?

Speculatively, temperature could confound or be a rival hypothesis in a few ways. It would influence what could be in solution, pollutants as well as things that offset them. It could be what varies across the parts of rivers or between rivers. It might differentially influence survival or breed

Re: What is an experiment ?

Art Kendall wrote: [snip good points] > in your quasi-experiment you can possibly contrast different levels of specific > pollutants, as well as kinds of pollutants, in different rivers at different > times. > I'm not a biologist, but I would be amazed if temperature did not affect > populatio

Re: odds vs probabilities

hi, thanks. sorry if I posed the question poorly. actually, what I'm looking for is an intuitive understanding of when to use odds and when probabilities. I know that probs have a problem in that they don't make multiplicative sense: for instance, assume I have a probability of winning of 55%; i

Re: What is an experiment ?

It depends on which science. In social, behavioral, industrial, and many health related fields, the distinction is sharply drawn between true experiments where there is active manipulation of one or more treatment independent variables and random assignment of cases to treatment. (also, it simpli

Re: What is an experiment ?

Jay Tanzman wrote: >I agree that you can test a hypothesis by using an observational study, but >that >does not make it an experiment. The original poster was looking for a >definition to use in a lecture, and an experiment, by definition, involes >assignment of treatments to experimental units.

Re: If T-Test can not be applied

Art Kendall wrote: >In SPSS output ignore the lines for equal variances, and use the lines for >unequal variances. Last year on this group, there was an interesting dataset posted, in which the equal and unequal variance t tests give very different results: Temperatures from Portion 1 of a st

Re: SPC control limits

Inasmuch as the objective is to 'drain the swamp' - reduce product & process variation, I find that in practice Wheeler's suggestion of focus on causes of that variation is on the mark.  the procedure from the old Ford Manual, and I believe the 6th & 7th Ed. of Grant & Leavenworth, puts the focus

Re: Question on CDF

Henry <[EMAIL PROTECTED]> wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > I was trying to suggest that he meant the slope of the CDF was the > height of the PDF. Oh, okay. Yes, that would be correct, but it shouldn't be called probability! Glen ===

Re: Question on CDF

On Sat, 23 Feb 2002 00:27:00 +1100, "Glen Barnett" <[EMAIL PROTECTED]> wrote: > >Henry <[EMAIL PROTECTED]> wrote in message >[EMAIL PROTECTED]">news:[EMAIL PROTECTED]... >> On Fri, 22 Feb 2002 08:55:42 +1100, "Glen Barnett" >> <[EMAIL PROTECTED]> wrote: >> >> >Bob <[EMAIL PROTECTED]> wrote in mes

Re: What is an experiment ?

SSCHEINE wrote: > > Let me take a (somewhat) contrarian position to those previously > expressed. An experiment is any test of a hypothesis. An experiment can > involve the use of observational (unmanipulated) data, as long as the > hypothesis is clearly stated prior to the collection of the da

RE: SPC control limits

Title: RE: SPC control limits Jay Warner writes: >The 'party line' is to take the first 30 or so points, calculate >limits, throw out any outside ones & add more at the end, until you >have 30 points, all of which are inside the control limits. Actually, I have hea

Re: Evaluation of skating

On 19 Feb 2002 15:14:01 -0800, [EMAIL PROTECTED] (Trevor Bond) wrote: [ snip, much ] > affected who won the gold medal. In fact, Looney (1994, p. 156) > concluded: > "all of the judges with an Eastern block or communistic background > not only ranked Baiul better than expected, but ranked Ker

Re: What is an experiment ?

Let me take a (somewhat) contrarian position to those previously expressed. An experiment is any test of a hypothesis. An experiment can involve the use of observational (unmanipulated) data, as long as the hypothesis is clearly stated prior to the collection of the data. While it is true that an

Re: Question on CDF

Henry <[EMAIL PROTECTED]> wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > On Fri, 22 Feb 2002 08:55:42 +1100, "Glen Barnett" > <[EMAIL PROTECTED]> wrote: > > >Bob <[EMAIL PROTECTED]> wrote in message > >[EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > >> A straight line CDF would im

Re: covariates !!

Rich Ulrich wrote: > I've always done this in SPSS (6.1 and earlier) with > ANOVA vara by grps(1,4) with covar/ Likewise. However, as I'm in a funny mood, it occurred to me that you could use the residuals from correlating the covariates with the separate grooup scores as input to a Mann-Whi

Re: Efficient convergence method

OK. You have a case where you sample from a 'population' of times from situation A a number of times, and from Situation B a number of times. Maybe C, D, etc. too. To compare 2 of these babies, use a t test. Keep sample size (n's of each) about equal, and go for it. Student 't' test is pretty

RE: Chi-square chart in Excel

sure is easy in minitab ... one can draw a very nice curve (it's easy but, hard to post here) but, to make a distribution easy for viewing we can MTB > rand 10 c1; <<< generated 10 values from SUBC> chis 4. <<< a chi square distribution with 4 degrees of freedom MTB > dotp c1 Dotplot:

Re: double exponential smoothing

Yvette wrote: >Prediction Model using double exponential smoothing to estimate the >linear trend in prices (as originally reported) and extending the >trend to future years. The base period is about 8-10 years and a >smoothing constant needs to be used to make the trend fairly >responsive to ch

RE: Chi-square chart in Excel

-Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Ronny Richardson Sent: Wednesday, February 20, 2002 7:29 PM To: [EMAIL PROTECTED] Subject: Chi-square chart in Excel Can anyone tell me how to produce a chart of the chi-square distribution in Excel? (I k

Re: Probabilities

In article <[EMAIL PROTECTED]>, Zachary Agatstein <[EMAIL PROTECTED]> wrote: >Can you help me solve this problem: >There are 8 baskets and 4 apples. Thrown at random, 3 of the 4 apples >can go to any basket. The 4th apple, however, can only be thrown into >baskets 1 through 4. What is the pro

Re: How to test whether f(X,Y)=f(X)f(Y) is true??

On Wed, 20 Feb 2002 22:21:38 -, "Chia C Chong" <[EMAIL PROTECTED]> wrote: [snip, various discussion before] > > I have an example of data of 2 RVs. When I tested the correlation between > them, by simply find the correlation coefficient, it shows that the > correlation coefficient is so smal

Re: Question on CDF

On Fri, 22 Feb 2002 08:55:42 +1100, "Glen Barnett" <[EMAIL PROTECTED]> wrote: >Bob <[EMAIL PROTECTED]> wrote in message >[EMAIL PROTECTED]">news:[EMAIL PROTECTED]... >> A straight line CDF would imply the data is uniformly distributed, >> that is, the probability of one event is the same as the p

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