def mae(self, scores: Union[List[float], List[List]]) -> float:
        """
        Calculate the mean absolute error. Can be used for meta-evaluation.

        Args:
            scores (List[float]): scores returned by feedback function

        Returns:
            float: Mean absolute error
        """

        # TODO: refactor this, this is to deal with COT type of response from feedback functions
        if isinstance(scores[0], List):
            scores = [score for score, _ in scores]
            print(f"flatten scores: {scores}")

        return np.mean(np.abs(np.array(scores) - np.array(self.true_labels)))

        Calculate the mean absolute error. Can be used for meta-evaluation.

        Args:
            scores (List[float]): scores returned by feedback function

        Returns:
            float: Mean absolute error
        
src/feedback/trulens/feedback/groundtruth.py