def compute_meandiff_bias_correction(bootstraps, effsize):
    """
    Computes the bias correction required for the BCa method
    of confidence interval construction.

    Keywords
    --------
    bootstraps: array-like
        An numerical iterable, comprising bootstrap resamples
        of the effect size.

    effsize: numeric
        The effect size for the original sample.


    Returns
    -------
    bias: numeric
        The bias correction value for the given bootstraps
        and effect size.

    """
    from scipy.stats import norm
    from numpy import array
    B = array(bootstraps)
    prop_less_than_es = sum(B < effsize) / len(B)
    return norm.ppf(prop_less_than_es)
