@staticmethod
def is_not_certain(fragment, certainty_threshold):
    """State if a fragment has been assigned with sufficient certainty

        Parameters
        ----------
        fragment : Fragment object
            Collection of images related to the same individual
        certainty_threshold : float
            Lower boundary in [0,1] for the certainty of a fragment

        Returns
        -------
        is_not_certain_flag : bool
            True if the fragment is assigned with high enough certainty

        """
    return fragment.certainty < certainty_threshold
