# [Rd] anova in model simplification in glm (PR#1087)

**menstav@hotmail.com
**
menstav@hotmail.com

*Sat, 8 Sep 2001 02:03:32 +0200 (MET DST)*

Full_Name: Menelaos Stavrinides
Version: 1.3. 1
OS: Windows 98
Submission from: (NULL) (193.129.76.90)
When model simplification is used in glm (binomial errors) and anova is used two
compare two competitive models one can use either an "F" or a "Chi" test.
R always performs an F test (Although when test="Chi" the test is labeled as
Chi, there isn't any difference between F and Chi test)
Let us assume model1 and model2, where model2 a simplified version of model1
model1_glm(y~factor1*factor2,binomial)
model2_update(model1,~.-factor2)
anova(model1,model2,test="F")# will give the same result as
anova(model1,model2,test="Chi")
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