[R] reference category in binomal glm

Prof Brian Ripley ripley at stats.ox.ac.uk
Tue May 27 13:25:15 CEST 2014


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]]
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>


-- 
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)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595



More information about the R-help mailing list