def star(v):
    """
    Statistical evidence categories for Bayes Factor

    Returns
    -------
    str
      For Bayes Factors larger than 1, returns a string
      with the number of stars corresponding to common interpretation
      of the Bayes Factor.
    """
    if v > 100:
        return '***'
    elif v > 30:
        return '**'
    elif v > 10:
        return '*'
    return ' '
