in the programs I know (i.e. R statistics) the default numbers of groups to use in Hosmer and Lemeshow test (goodness-of-fit for models, especially logistic regression) is set to 10. I wonder why or if I should define another number for my data. Because I also found that the number of groups is really important for the p-value which results from this.
Does it depend on the amount of data, the degrees of freedom, or something else?