Date: Dec 7, 2012 6:36 PM
Author: Ray Koopman
Subject: Re: Must we say S,N instead of N,S if we've said "Subset x MoSS" (not<br> MoSS x Subset) ???

On Dec 7, 12:13 pm, djh <halitsk...@att.net> wrote:
> It didn't occure to me to ask if we must say S,N (instead of N,S) if
> we've said "Subset x MoSS" (not MoSS x Subset).
>
> If we're obligated to do so, then of course the two tables must be
> presented as:
>
> SE and p values for u^2 in regression c on (e,u,u*e,u^2) for each
> value of subset x MoSS | (Fold,Set,Len) = (all,all,all)
> --------------------
> Subset
> x u^2
> MoSS SE p
>
> S,N 35.17 0.457
> C,N 38.19 0.416
> S,R 36.88 0.434
> C,R 34.69 0.438
> --------------------
>
> SE and p values for u*e in the regression c on (u,e,u*e), for each
> value of subset x MoSS | (Fold,Set,Len) = (all,all,all)
> --------------------
> Subset
> x u*e
> MoSS SE p
>
> S,N 0.491 0.454
> C,N 0.602 0.462
> S,R 0.547 0.463
> C,R 0.512 0.478


1. What does "(Fold,Set,Len) = (all,all,all)" mean?

2. Something's wrong somewhere. Those p's are too similar to one
another, and are too large to be consistent with the other results
you've been reporting.

3. If all the p's for u^2 are truly that big then you should probably
drop the quadratic model. Model selection generally starts with the
most complicated model and works down. In particular, you should not
be considering any results from regressing c on (u,u^2) if e matters.

4. SEP = sqrt[Residual Sum of Squares / df]
= sqrt[Residual Mean Square]
Are you sure Ivo's program doesn't give that as optional output?

5. Let the constant in the input to Ivo's program default to 1.

6. I have a hunch that Het may be related to a Subset x Fold
interaction, where the d.v. is the average slope.

7. Your forthcoming explanation "using reasoning based on the
behavior of the average slope Auq of c on (u,u^2) and the covariance
AubC of e and u in c on (u,e,u*e)" will probably go right over my
head, because I have only a hunch about what the average slope Auq
of c on (u,u^2) might mean, and not a clue about what the covariance
AubC of e and u in c on (u,e,u*e) might mean.

Enough for now.