I’m using a logistic regression nominal model for a response variable (pregnant/not-pregnant). My independent variables are: Time of insemination + Production type + interaction. When TOI (48, 52, 56h) is described as a nominal variable both PT and the interaction are significant. When TOI is used is described as a ordinal variable, only the interaction is significant. Why is this relevant to the analysis? I thought the type of logistic regression to be used (nominal or ordinal) was determined only by the data nature of the response variable. Many thanks for any help I can get.