Dear list
I have two glmer models, one with a fixed factor (targetWordFactor) and one
without, and I am comparing them using the anova function to get the LRT
results for the fixed effect of targetWordFactor. The anova results are
showing a chi-square value of 0 and p value of 1. Is this result possible,
or is it perhaps a sign that I've done something wrong?
Here are the anova results:
anova(accModelNullWord,accModelWord)
# Df AIC BIC logLik deviance Chisq
Chi Df Pr(>Chisq)
# accModelNullWord 13 977.59 1067.0 -475.8 951.59
# accModelWord 15 990.61 1093.8 -480.3 960.61 0 2
1
The targetWordFactor fixed factor has 3 levels (2 contrasts), so the
degrees of freedom in the anova result look correct to me. Here are the
model specifications:
contrasts(pauseDetValidNoFillersExcluded$targetWordFactor)
# WW NW
# W 0 0
# WW 1 0
# NW 0 1
accModelNullWord <- glmer(correct ~ 1 +
(1 + targetWordFactor|subject) +
(1 + targetWordFactor|item),
data = pauseDetValidNoFillersExcluded,
family = binomial(link = "logit"),
control = glmerControl(optimizer="bobyqa",
optCtrl =
list(maxfun=2e5)))
accModelWord <- glmer(correct ~ 1 + targetWordFactor +
(1 + targetWordFactor|subject) +
(1 + targetWordFactor|item),
data = pauseDetValidNoFillersExcluded,
family = binomial(link = "logit"),
control = glmerControl(optimizer="bobyqa",
optCtrl = list(maxfun=2e5)))
Apologies if this question has been asked before - I did search the list
but couldn't find anything.
Many thanks,
Becky
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