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