Mediation with an ordinal mediator( low, normal and high) and continuous predictor and outcome, any suggested method will be appreciated.
Is the mediator ordinal in essence, or just superficially so because of the way it was recorded? If the latter, you might posit a latent continuous mediator, and treat the discretized ordinal value as an interval-censored measurement of that underlying continuous quantity.
The mediator was continuous, but we are interested in its ordinal case, low, normal and high.
How can I do it using R?
This is starting to sound more like the sort of thing people do in SAS.
What if RMSE= 0.463 and P-value (Chi-square) is zero, meanning that the model does not fit in a Structiral Equation Modeling? How we address this issue?