I am doing an ANCOVA model in order to explain the gap in a given distance. So I have a control group, and I have several quantitative variables, right now I am trying to evaluate the impact of the quantitative variables individually. But I think the results I get are incoherent, lest see:
Df Sum Sq Mean Sq F value Pr(>F) as.factor(groupe) 1 738.8 738.8 21.931 1.03e-05 *** BASE0008 1 36.6 36.6 1.087 0.29992 as.factor(groupe):BASE0008 1 270.0 270.0 8.015 0.00576 ** Residuals 87 2930.9 33.7
These are the results from the ANOVA table, we could say that the group has a significant effect so does the interaction, but when I look at the results of the regression model, I find this:
Estimate Std. Error t value Pr(>|t|) (Intercept) 1.16666 3.38404 0.345 0.73111 as.factor(groupe)NAV 4.48191 3.79515 1.181 0.24084 BASE0008 0.26027 0.08651 3.009 0.00343 ** as.factor(groupe)NAV:BASE0008 -0.26902 0.09503 -2.831 0.00576 **
Well, the interaction is still relevant, but it looks like there is not effect of the group and the quantitative variable is more important to determinate the output of the experiment. I want to know if my interpretation is accurate: What can I say about the group?