def _get_average_score(concept, _keywords):
    """Get average score of words in `concept`.

    Parameters
    ----------
    concept : str
        Input text.
    _keywords : dict
        Keywords as keys and its scores as values.

    Returns
    -------
    float
        Average score.

    """
    word_list = concept.split()
    word_counter = len(word_list)
    total = float(sum(_keywords[word] for word in word_list))
    return total / word_counter