}{n_1+n_2}\) and <em></em>\(f(z_p)\) denotes the density of the standard normal distribution at value <em></em>\(z_p\), which is the point for which <em></em>\(P(Z &gt; z_p) = p\), with <em></em>\(Z\) denoting a random variable following a standard normal distribution (Jacobs &amp; Viechtbauer, 2017).</p></li>
<li><p><code>transf.rpbtorbis</code>: transformation of point-biserial correlations to biserial correlations. Argument <code>pi</code> denotes the proportion of individuals falling into the first of t