Hi All,(adsbygoogle = window.adsbygoogle || []).push({});

I ran a binary logistic of Y on three different numerical variables A,B,C respectively. I am having an issue of separation of variables with all of them, meaning that there are values Ao,Bo, Co for each of A,B,C (different values for each, of course) so that for ## A>Ao, B>Bo, C>Co ## all the responses are successes (I guess this forces the slope to diverge to minus infinity for the slope of the curve to accommodate the abrupt change of 1 to 0). Then I increased the success levels to three: high, medium and low, to use an ordinal regression . But now I have a significant lack of fit, with p -->0 on the Chi-squared test. How does one interpret lack-of-fit issues with a Logistic Regression? I know that a lack of fit in a simple linear means that data is not linear but what does it mean for a Logistic? Does it mean the (log of) the data is not distributed like an S-curve ExpL/(1+ExpL) (##L=

\beta_0+ \beta_1 x+......##) ? If so, are there any standard , or any, alternatives (e.g for a distribution for the data). Any ideas?

**Physics Forums | Science Articles, Homework Help, Discussion**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# I Lack of Fit in Ordinal Regression -- Analysis/Alternatives?

Tags:

Have something to add?

Draft saved
Draft deleted

Loading...

Similar Threads for Lack Ordinal Regression |
---|

A Measures of Center/Spread in Categorical/Ordinal |

A Simmons notation for transfinite ordinals |

I Recursive Ordinals and Creativity |

A How can we construct ordinals after large Veblen? |

A Fundamental sequences for the Veblen hierarchy of ordinals |

**Physics Forums | Science Articles, Homework Help, Discussion**