Convergence of the iterations is determined by comparing the relative change in the coefficients and the change in the deviance to cutoff values. The iteration terminates if either change falls below the corresponding cutoffs. A limit is also imposed on the number of iterations. The analogy captured in the inheritance of the glim-proto prototype from the normal linear regression prototype is based primarily on the computational process, not the modeling process. As a result, several accessor methods inherited from the linear regression object refer to analogous components of the computational process, rather than analogous components of the model.
Some models permit the estimation of a scale parameter.
Most inherited methods for residuals, standard errors, etc., should make sense at least as approximations.