title: point biserial and p-value
body: <p>I am trying to get a point biserial correlation between a continuous vocabulary score and syntactic productivity (dichotomous: productive vs not_productive).</p>
  
  <p>I tried both the ltm packages</p>
  
  <pre><code>&gt; biserial.cor (lol$voc1_tvl, lol$synt, use = c("complete.obs")) 
  </code></pre>
  
  <p>and the polycor package</p>
  
  <pre><code>&gt; polyserial( lol$voc1_tvl, lol$synt, ML = FALSE, control = list(), std.err = FALSE, maxcor=.9999, bins=4)
  </code></pre>
  
  <p>The problem is that neither test gives me a p-value</p>
  
  <p>How could I run a point biserial correlation test and get the associated p-value or alternatively calculate the p-value myself?</p>