What does the useLaplace parameter do in the WEKA j48 algorithm?
<p>I am mining on a dataset using the j48 tree algorithm.</p>

<p>I have been trying to understand what the <code>useLaplace</code> parameter does. The only thing I have to go by is this:</p>

<blockquote>
  <p>Whether counts at leaves are smoothed based on LapLace</p>
</blockquote>

<p>which is just the documentation which WEKA has provided. I have some questions about this though:</p>

<ol>
<li>What are counts at leaves?</li>
<li>What is smoothing?</li>
<li>What is LapLace? Is it an algorithm used for smoothing?</li>
</ol>

<p>Everything I have found online doesn't really go into detail about what this parameter is actually doing, rather just explains that it "turns on Laplace smoothing."</p>