search for: trichotom

...times, i.e. 4 times (y1,y2, y3, y4), unfortunately suffering from some successive dropouts (i.e. the sample sizes varies for y1, y2, y3, and y4). For every y, two other variables (covariates) were also measured: x & z, and both do presumably exert an effect on y. At some cutoffs, x can also be trichotomized into 3 ordinal levels constituting a presumed factor (fx) influencing the level of y at all of the different measurings (1-4). x and fx are rather stable arcoss the 4 measurements whereas z is not. H0 is that x and fx are not influencing the level of y (i.e. explaining any variance of y) irresp...