# Tagged Questions

163 views

### QQ plot is consistent with normality when subgroups are non-normal

I have read that for a one way ANOVA, you should check that the model residuals are normally distributed. If the variance of each group is homogeneous then this implies that the residuals with each ...
197 views

### ANOVA:How to detect non-normality with a QQPlot in the presence of non-homogeneous variance

This is a pretty general question but, I often find statistical textbooks claiming that, in order to justify the within groups normality assumption of a one way ANOVA, you can look at a QQ plots of ...
67 views

### finding the residual variance after correcting ordinal data for sex

I have a data set organized as: males, females as groups. Each individual has a "score" that is ordinal, ranking 0,1, or in another case, 0,1,2. I need to find the residual variation after correcting ...
242 views

### Checking normality of residuals in 2x2 mixed methods ANOVA

I am running a 2x2 mixed method ANOVA (with one between-group factor and one within-group factor - time 1 and time 2). I want to check whether the assumption of normality of residuals is met. When I ...
201 views

### Weighted regression for categorical variables

I have been trying to use weighted regression on some data where there are three categorical variables with the lm(y ~ A*B*C) command in R. This was to try ...