Hey guys I'm trying to conduct an anova with:
"group" as factor (1,2,3)
and "SI_ZI" (difference scores for Symptom intensity)
note: scores can be negative
the code:
anova_1 <- aov(df$group~df$SI_Z1)
the warnings (I'm sorry its in German but the words are equal to the englisch ones):
Warnmeldungen:
1: In model.response(mf, "numeric") :
Benutzung von type="numeric" wird für eine faktorielle Zielgröße ignoriert
2: In Ops.factor(y, z$residuals) : ‘-’ not meaningful for factors
However I tried to summarize the anova
summary(anova_1)
Fehler in levels(x) :
nur Nullen dürfen mit negativen Indizes gemischt werden
Does anybody understand what is wrong?
Thanks you in advance,
Laura