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2000-04-10 Thread Rex Boggs
unsubscribe edstat-l === This list is open to everyone. Occasionally, less thoughtful people send inappropriate messages. Please DO NOT COMPLAIN TO THE POSTMASTER about these messages because the postmaster has no way of

Re: hyp testing

2000-04-10 Thread Robert Dawson
Dennis Roberts asked, imagining a testing-free universe: what would the vast majority of folks who either do inferential work and/or teach it ... DO what analyses would they be doing? what would they be teaching? I wrote: * students would be told in their compulsory intro stats that

Re: hyp testing

2000-04-10 Thread Michael Granaas
On Fri, 7 Apr 2000, Chris Mecklin wrote: Among other things My point is that I want to show my class an example where they can see the pitfalls of making a decision based solely on a p-value. I don't want My favorite, not contrived example, has to do with vocational advice and gender. It

Re: hyp testing

2000-04-10 Thread Bruce Weaver
On 7 Apr 2000, dennis roberts wrote: i was not suggesting taking away from our arsenal of tricks ... but, since i was one of those old guys too ... i am wondering if we were mostly lead astray ...? the more i work with statistical methods, the less i see any meaningful (at the level of

Re: hyp testing

2000-04-10 Thread Michael Granaas
On Fri, 7 Apr 2000, dennis roberts wrote: At 04:00 PM 4/7/00 -0500, Michael Granaas wrote: But whatever form hypothesis testing takes it must first and formost be viewed in the context of the question being asked. this seems to be the key to REinventing ourselves ... make sure the

Re: hyp testing

2000-04-10 Thread Robert Dawson
Bruce Weaver wrote (in part): ...Negative priming is measured as a response time difference between 2 conditions in an experiment. The difference is typically between about 20 and 40 milliseconds... The researcher KNOWS that a lot of other things affect response

Re: hyp testing

2000-04-10 Thread dennis roberts
the term 'null' does NOT mean 0 (zero) ... though it is misconstrued that way the term 'null' means a hypothesis that is the straw dog case ... for which we are hoping that sample data will allow us to NULLIFY ... in some cases, the null happens to be 0 ... but in many cases, it does not

Re: hyp testing

2000-04-10 Thread Robert Dawson
Dennis Roberts wrote: the term 'null' does NOT mean 0 (zero) ... though it is misconstrued that way the term 'null' means a hypothesis that is the straw dog case ... for which we are hoping that sample data will allow us to NULLIFY ... in some cases, the null happens to be 0 ... but in many

Re: hyp testing

2000-04-10 Thread Michael Granaas
On Mon, 10 Apr 2000, Robert Dawson wrote: Dennis Roberts wrote: the term 'null' does NOT mean 0 (zero) ... though it is misconstrued that way the term 'null' means a hypothesis that is the straw dog case ... for which we are hoping that sample data will allow us to NULLIFY ... in

Re: hyp testing

2000-04-10 Thread Robert Dawson
Dennis Roberts wrote: if you are interested in the relationship between heights and weights of people, in the larger population ... the notion that we test this against a null of rho=0 is not credible ... in fact, it is rather stupid ... a more sensible null would be perhaps a rho of .5 ...

Re: hyp testing

2000-04-10 Thread Robert Dawson
Michael Granaas wrote: My grandmother could have told me that the mean height for men and women was not the same (zero difference). So based on prior evidence I hypothesize that the actual difference is 3 inches (mu1 - mu2 = 3) and use that for my null hypothesis. True, I can reduce this

Re: What to do about simple techniques

2000-04-10 Thread Paul R Swank
I am new to the list so I am jumping into the middle of this. However, we have to start teaching hypothesis testing somewhere. Even if it goes the way of the Edsel, it will be a slow death because many of us will continue to use when we feel it is appropriate to the question. However, I tell my

Re: hyp testing

2000-04-10 Thread dennis roberts
At 01:16 PM 4/10/00 -0300, Robert Dawson wrote: No if you have to start "a more sensible null would be perhaps" you almost surely do not have a hypothesis worth testing. now we get to the crux of the matter ... WHY do we need a null ... or any hypothesis ... (credible and/or

Re: hyp testing

2000-04-10 Thread dennis roberts
At 01:16 PM 4/10/00 -0300, Robert Dawson wrote: both leave the listener wondering "why 0.5?" If the only answer is "well, it was a round number close enough to x bar [or "to my guesstimate before the experiment"] not to seem silly, but far enough away that I thought I could reject it." then the

Sensible nulls

2000-04-10 Thread Michael Granaas
I, and I think Dennis, are arguing that when we test a hypothesis we should have a null hypothesis that is plausibly true. A hypothesis that reflects some sort of an effect size estimate where such an estimate is meaningful. If I understand correctly Robert is arguing that we should always

Re: Sensible nulls

2000-04-10 Thread Michael Granaas
On Mon, 10 Apr 2000, Robert Dawson wrote: Michael Granaas wrote: H0: being in the target population has no effect on sexual dimorphism in height Ha: being in the target population does affect sexual dimorphism in height I want to see if I am interpreting your meaning correctly.

Re: hyp testing

2000-04-10 Thread Donald F. Burrill
On Mon, 10 Apr 2000, dennis roberts wrote in part: .. the fact that we create a null and test a null does NOT imply that we are therefore testing some effect size ... Of course not. One does not TEST an effect size, one ESTIMATES it. And it is useful to do so only if one has found it not

Re: 3-D regression planes graph,

2000-04-10 Thread Jon Cryer
The free ARC software from the University of Minnesota will do some of this. Look at http://stat.umn.edu/ARCHIVES/archives.html Jon Cryer At 01:59 PM 4/10/00 -0500, you wrote: Hello all, I'm looking for software that can display a 3-D regression environment (x, y, and z variables) and draw a

Re: hyp testing

2000-04-10 Thread Michael Granaas
My comments are about half-way down. Michael On Mon, 10 Apr 2000, Robert Dawson wrote: Dennis Roberts wrote: now we get to the crux of the matter ... WHY do we need a null ... or any hypothesis ... (credible and/or sensible) to test??? what is the scientific need for this? what is

scientific method

2000-04-10 Thread dennis roberts
here are a few (fastly found i admit) urls about scientific method ... some are quite interesting http://dharma-haven.org/science/myth-of-scientific-method.htm#Overview http://teacher.nsrl.rochester.edu/phy_labs/AppendixE/AppendixE.html http://idt.net/~nelsonb/bridgman.html

Re: hyp testing

2000-04-10 Thread Rich Ulrich
Just because Dennis has trouble with the null hypothesis, that does not mean that it is a bad idea to use them. On 10 Apr 2000 08:41:06 -0700, [EMAIL PROTECTED] (dennis roberts) wrote: the term 'null' does NOT mean 0 (zero) ... though it is misconstrued that way the term 'null' means a

Re: hyp testing

2000-04-10 Thread dennis roberts
the logic behind the null hypothesis method is flawed ... IF you are looking for truth AND you keep following the logic of testing AGAINST a null ... first, say you reject the null of rho = 0 ... then, LOGICALLY ... this says that since we don't know what truth is ... just what we think it

Re: hyp testing

2000-04-10 Thread David A. Heiser
- Original Message - From: Michael Granaas [EMAIL PROTECTED] Our current verbal lables leave much to be desired. Depending on who you ask the "null hypothesis" is a) a hypothesis of no effect (nil hypothesis) b) an a priori false hypothesis to be rejected (straw dog hypothesis)

cluster analysis

2000-04-10 Thread Elisa Wood
Can anyone help with good resources on the web, journals, books, etc on cluster analysis - simularity and ordination. Any recommended programs for this type of analysis too. Cheers Elisa Wood === This list is open to