[R] reference category in binomal glm

[Prof Brian Ripley]

On 27/05/2014 09:51, Xebar Saram wrote:
> Hi all
>
> i know this is probably a silly question but im wondering what is the
> 'reference' category when you run a binomal glm. that is my outcome/DV is
> 0,1 and i run a regression and get coefficients. do the coefficients refer
> to the probability to get 0 or 1?

?binomial in R-devel says

      For the ‘binomial’ and ‘quasibinomial’ families the response can
      be specified in one of three ways:

        1. As a factor: ‘success’ is interpreted as the factor not
           having the first level (and hence usually of having the
           second level).

        2. As a numerical vector with values between ‘0’ and ‘1’,
           interpreted as the proportion of successful cases (with the
           total number of cases given by the ‘weights’).

        3. As a two-column integer matrix.  The first column gives the
           number of successes and the second the number of failures.



>
> thanks so much in advance
>
> Z
>
> 	[[alternative HTML version deleted]]
>
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-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
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