[R] Standardized beta-coefficients in regression

[Prof Brian Ripley]

On Mon, 16 Jan 2006, Dr. Walter H. Schreiber wrote:

> Hello list,
>
> I am used to give a lot of attention to the standardized regression
> coefficients, which in SPSS are listed automatically.

I do wonder why?  Most people I have encountered who do that are 
interpreting them in invalid ways.

> Is there alternative to running the last two lines in the following example to
> get all the information?

Yes, but why do you want one?  (You don't need summary, just coef, in the 
second line, and you also do not need an intercept.)  For a single 
regressor as here, just cor(ctl, trt).

> ctl <- c(4.17,5.58,5.18,6.11,4.50,4.61,5.17,4.53,5.33,5.14)
> trt <- c(4.81,4.17,4.41,3.59,5.87,3.83,6.03,4.89,4.32,4.69)
> summary( lm(ctl ~ trt) )
> summary( lm(scale(ctl) ~ scale(trt)) )

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
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