A method for creating a Gaussian process model as a data-based functional model for an output quantity that is to be modeled, based on training data in an input data space, including providing training data having training data points and output values, assigned to the training data points, of one or more output quantities; ascertaining a point density that is a function of the position of the training data points in the input data space; ascertaining a length scale function for each input quantity of the training data as a function of the point density; and generating a Gaussian process model from the training data and the output data of the output quantity to be modeled, based on the ascertained length scale functions.