def _get_entry_scores(self):
        """Takes entries from self._entries and returns a list of scores (or
        output scores, if based on grades)"""
        if self.get_gradebook_column().get_grade_system().is_based_on_grades():
            return [e.get_grade().get_output_score() for e in self._entries if e.is_graded()]
        else:
            return [e.get_score() for e in self._entries if e.is_graded()]