[R] interpreting results of regression using ordinal predictors in R

[David Winsemius]

On Jan 2, 2013, at 10:09 PM, Bert Gunter wrote:

> Below ...
>
> -- Bert
>
> On Wed, Jan 2, 2013 at 9:54 PM, David Winsemius <dwinsemius at comcast.net 
> > wrote:
> ...
>
> Search on "orthogonal polynomials".
>
> Yes, but this does not explain what these have to do with ordered  
> factors and contrasts in a linear model.
> That information is contained in "An Introduction to R," the  
> tutorial that ships with R and which the OP should have perused  
> before posting. Detailed explanation beyond that is too technical  
> for here, I would say.

The material in "Intro to R" is, I think all will agree, rather  
sketchy. I think this strategy will be more productive:

http://lmgtfy.com/?q=%22orthogonal+polynomials%22+linear+models

Second link was:

www.stats.ox.ac.uk/pub/StatMeth/Linear2_04.pdf

-- 
David.

>
> -- Bert
>
>
>
>
> Note that my question is not on lm (I think), but rather on how lm
> outputs the results of regressions involving ordered predictors. Some
> references would be great.
>
> Please post responses to this mailing list.
>
>
> As always.
>
> Thanks very much again for all your help!
>
>
> -- 
>
>
> David Winsemius, MD
> Alameda, CA, USA
>
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>
>
> -- 
>
> Bert Gunter
> Genentech Nonclinical Biostatistics
>
> Internal Contact Info:
> Phone: 467-7374
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>

David Winsemius, MD
Alameda, CA, USA