[R-sig-eco] Effect size for factors in lm and glm

[Manuel Spínola]

Dear list members,

I really like the idea of presenting the effect size (point and interval 
estimation) instead of P values, but I am wondering if there is any 
package in R that calculate effect size from lm and glm when the 
explanatory variables are factors.
I know that there is a package called "effects"  but when working with 
factors the calculation and display is not for the effect size (the 
difference between 2 levels of a factor a its confidence interval).
I am thinking in a calculation that take into consideration the 
variance-covariance matrix.
Any hint on this.
Thank you very much in advance.
Best,

Manuel

-- 
Manuel Spínola, Ph.D.
Instituto Internacional en Conservación y Manejo de Vida Silvestre
Universidad Nacional
Apartado 1350-3000
Heredia
COSTA RICA
mspinola at una.ac.cr
mspinola10 at gmail.com
Teléfono: (506) 2277-3598
Fax: (506) 2237-7036