[Rd] Bug in calculation of overdispersion for quasibinomial grouped
Ulrike Grömping
groemping at bht-berlin.de
Mon Apr 26 22:36:13 CEST 2010
A quick addition:
SAS PROC LOGISTIC with option SCALE=PEARSON only calculates what R
calculates in the grouped version; this is forced by refusing to
calculate a FI estimate for ungrouped data, unless an AGGREGATE option
is specified.
Apparently, SAS has decided for one model (not the one I am most
familiar with), while the R version makes the model decision depend on
the format of the data. As the family in glm is called quasibinomial, I
would have expected it to conduct the adhoc adjustment.
Best, Ulrike
--
***********************************************
* Ulrike Groemping *
* BHT Berlin - University of Applied Sciences *
***********************************************
* +49 (30) 39404863 (Home Office) *
* +49 (30) 4504 5127 (BHT) *
***********************************************
* http://prof.tfh-berlin.de/groemping *
* groemping at bht-berlin.de *
More information about the R-devel
mailing list