1. A computerized method for generating a data-based function model, comprising: providing a first data-based partial model ascertained from a first training data record; providing at least one additional training data record; perform the following for the at least one additional training data record: ascertaining a difference training data record having training data which correspond to the difference between the output value of the at least one additional training data record and the function value of the sum of the partial function values (f first — partial — model (x), f second partial model (x)) of the first data-based partial model and previously ascertained at least one data-based partial model at each of the measuring points of the relevant training data record; and ascertaining an additional data-based partial model from the difference training data record; and forming a sum (f(x)) from the first data-based partial model and the ascertained additional data-based partial model, in order to obtain the data-based function model.