predicting with interval data with a limited number of levels.


No cake for spunky
"To visualize how receipt of key services was associated with employment outcomes, we calculated the rate of employment at VR exit for each group based on a count of key services received (zero to four services)." So they have a predictor that ranges from 0-4. This is not interval data, it is bounded on both sides, but it is not really likert scale data either. I am not sure about the validity of using a predictor this way (essentially its a count). I don't think it makes a lot of sense to convert this to a set of dummies.

Can you use a 4 level count this way in linear regression (they actually used it for logistic regression). I know there are no distributional assumptions about predictors, but I have heard it argued that it can create various problems to treat this as interval data. This is an issue I have wondered about for years.