I am working on an Ordinal logistic regression model. I have an outcome variable with 4 categories and they are ordered. My predictor or explanatory variables are 11 in number with the 11th predictor being a categorical variable with 4 levels.
I am taking a stepwise addition approach where in I am starting by adding one predictor in the model and proceeding to include or exclude further predictors depending on BIC statistics. I am including or excluding variables i.e. predictors in the model depending on the comparison of individual model BIC values.
However, as I build my model using 11th predictor, I get an error that "attempt to find suitable starting values failed" and a warning message that "glm.fit: algorithm did not converge".
The output is pasted below for your reference:
model2.11 <- polr(formula = Q13 ~ Q11, data = mydata13, method = "logistic") Error in polr(formula = Q13 ~ Q11, data = mydata13, method = "logistic") : attempt to find suitable starting values failed In addition: Warning message: glm.fit: algorithm did not converge
Please let me know where I might be going wrong. All suggestions are welcome. Thanks in advance.