MZodet@ahrq.gov
2003-Jun-19 21:18 UTC
[R] Statistical Models: Ordered vs. Non-Ordered Factors
I'd like to understand better how ordered and non-ordered factors are treated differently when included as explanatory variables in statistical models. Also, it appears as though glm [family=binomial] (base) treats ordered factors differently than lrm (design). For example, when fitting the same model with each function the inclusion of an ordered factor results in considerably different coefficients. If I do not specify the factor as ordered my resulting coefficients (glm and lrm) are essentially identical. Any personal insight or good references would be much appreciated. Thanks. Marc [[alternative HTML version deleted]]