def calculate_AICc(AIC, number_of_parameters, effective_number_of_data_points):
    """
    AIC is the Aikaike Information Criterion and AICc the corrected
    criterion for small numbers of observations
    """
    return AIC + 2.*number_of_parameters*(number_of_parameters + 1.) / (effective_number_of_data_points - number_of_parameters - 1.)