I am currently using the nominal_test function, in the ordinal package, to test for the proportional odds assumption but have encountered a problem.
Here is my code:
feelingsmodel<-clm(Feelings ~ Gender + Location + Role + FarmType + Age + Income + Knowledge, data = data, na.action=na.exclude, Hess = TRUE , link = "logit") nominal_test(feelingsmodel)
And my output:
Tests of nominal effects formula: Feelings ~ Gender + Location + Role + FarmType + Age + Income + Knowledge Df logLik AIC LRT Pr(>Chi) <none> -629.12 1320.2 Gender 5 -625.92 1323.8 6.3829 0.27073 Location Role 15 -627.18 1346.3 3.8806 0.99810 FarmType Age 15 -618.83 1329.7 20.5712 0.15110 Income 10 -617.82 1317.6 22.5870 0.01238 * Knowledge
For some explanatory variables (Location, FarmType and Knowledge) there seems to be no output. When I run similar models different output for different explanatory variables is omitted seemingly at random. How I could solve this problem and get a p value for all explanatory variables?