to test the significance of different logit models the LogLikelihood (LL) of those models is subtracted to calculate chi square. E.g.: 2(LLnew - LLold).

After that the degrees of freedom are calculated to consider them in the chi square table and to check if the difference between those models is significant or not.

But what do I if there is no change in the estimated parameters but solely in the number of holdout tasks (eg. 1 vs 2)? How do I consider the degrees of freedom for calculating the significance of model change?

Thanks a lot!