def word_overlap(left_words, right_words):
    """Returns the Jaccard similarity between two sets.

    Note
    ----
    The topics are considered sets of words, and not distributions.

    Parameters
    ----------
    left_words : set
        The set of words for first topic

    right_words : set
        The set of words for the other topic


    Returns
    -------
    jaccard_similarity : float
    """
    intersection = len(left_words.intersection(right_words))
    union = len(left_words.union(right_words))
    jaccard = intersection / union
    return jaccard