Thank for your response! What do you exactly mean with 'model-fitting approach'? I want to find a model that is fitting the data, we suppose it's linear with interaction effects. In the meanwhile, I adjusted the 'stder' in the dataset to 'w' and I changed the values to 1/stderror. This is what I have so far: data trial; input x1$ x2$ x3$ y w; datalines; ... ... ... ; proc glm data=trial; class x1 x3; weight w; model y=x1 x2 x3 x1*x2 x1*x3 x2*x3 / solution; output out=trialresults p=pk ; proc print data=trialresults; run; Now SAS is giving me this error, although all the values of x2 are numeric: ERROR: Variable x2 should be either numeric or specified in the CLASS statement. Do I also need to state that x2 is numeric? It's also giving me this error, although I stated a model (or at least that's what I think): ERROR: A MODEL statement must be given. What could be wrong?
... View more