jamovi

Hi all,
I'm exploring the ordinal regression analysis in Jamovi, and I'm wondering what's the Overall Model Test from Model Fit tab. Is it the same as the Score Test for the Proportional Odds Assumption from SAS?
Thanks in advance!

Hey @dansquared,
as you surely know, under the hood of jamovi beats R.
Here, in the ordinal logistic regression sources, you find the call to the polr() function of the MASS package:
https://github.com/jamovi/jmv/blob/master/R/logregord.b.R#L63-L68

Description
Fits a logistic or probit regression model to an ordered factor response. The default logistic case is proportional odds logistic regression, after which the function is named.

Cheers,
Maurizio

Hey @MAgojam, thanks a lot for pointing me the code behind the ordinal regression, but I'm still having a hard time figuring out the Overall Model Test. It's testing against a null model, but what's this null model?

Hello @dansquared, overall model test uses the likelihood ratio chi-square and it compares the full model against the null model with no predictors.

Hi @tegedik, oh I see! That makes sense, thanks!