<p>The unfortunate collision of the word "kernel" as in "kernel density estimate" and the separate use as in "reproducing kernel Hilbert space" is making the <a href="https://stats.stackexchange.com/questions/tagged/kernel" class="post-tag" title="show questions tagged &#39;kernel&#39;" rel="tag">kernel</a>  tag kind of confusing.</p>

<p>The tag wiki summary has as its second sentence</p>

<blockquote>
  <p>DO NOT USE this tag for [kernel-trick] which is reserved for kernel methods in machine learning.</p>
</blockquote>

<p>(as was @gung's suggestion <a href="https://stats.meta.stackexchange.com/a/2168/9964">here</a>). But the first page of the "active" page for the tag currently shows only 4/15 questions about kernel smoothing and the remaining 11 about RKHS kernel functions. So it seems that the outcome of <a href="https://stats.meta.stackexchange.com/q/2167/9964">this discussion</a> from last fall wasn't enough to clean up the tag.</p>

<p>The current space of kernel-related tags seems to be:</p>

<ul>
<li><a href="https://stats.stackexchange.com/questions/tagged/kernel" class="post-tag" title="show questions tagged &#39;kernel&#39;" rel="tag">kernel</a>, supposed to be for KDE-style kernel functions but in practice a mix of both (264 questions)</li>
<li><a href="https://stats.stackexchange.com/questions/tagged/kernel-trick" class="post-tag" title="show questions tagged &#39;kernel-trick&#39;" rel="tag">kernel-trick</a>, for RKHS-style kernel functions and related issues (85 questions)</li>
<li><a href="https://stats.stackexchange.com/questions/tagged/kernel-density-estimate" class="post-tag" title="show questions tagged &#39;kernel-density-estimate&#39;" rel="tag">kernel-density-estimate</a>, for KDE in general (78 questions)</li>
<li><a href="https://stats.stackexchange.com/questions/tagged/kernel-regression" class="post-tag" title="show questions tagged &#39;kernel-regression&#39;" rel="tag">kernel-regression</a>, 5 questions of which 4 are about Nadaraya-Watson kernel regression (analogous to KDE) and 1 is about RKHS kernels</li>
</ul>

<p>I think the name <a href="https://stats.stackexchange.com/questions/tagged/kernel-trick" class="post-tag" title="show questions tagged &#39;kernel-trick&#39;" rel="tag">kernel-trick</a> isn't the most intuitive name when you're thinking about kernel methods, especially when there's the <a href="https://stats.stackexchange.com/questions/tagged/kernel" class="post-tag" title="show questions tagged &#39;kernel&#39;" rel="tag">kernel</a> tag popping up first. So I propose either:</p>

<ol>
<li>renaming <a href="https://stats.stackexchange.com/questions/tagged/kernel" class="post-tag" title="show questions tagged &#39;kernel&#39;" rel="tag">kernel</a> to <a href="https://stats.stackexchange.com/questions/tagged/kernel-smoothing" class="post-tag" title="show questions tagged &#39;kernel-smoothing&#39;" rel="tag">kernel-smoothing</a></li>
<li>completely removing <a href="https://stats.stackexchange.com/questions/tagged/kernel" class="post-tag" title="show questions tagged &#39;kernel&#39;" rel="tag">kernel</a> and sorting it into <a href="https://stats.stackexchange.com/questions/tagged/kernel-density-estimate" class="post-tag" title="show questions tagged &#39;kernel-density-estimate&#39;" rel="tag">kernel-density-estimate</a> and <a href="https://stats.stackexchange.com/questions/tagged/kernel-regression" class="post-tag" title="show questions tagged &#39;kernel-regression&#39;" rel="tag">kernel-regression</a> as appropriate.</li>
</ol>

<p>In either case, people who should be using <a href="https://stats.stackexchange.com/questions/tagged/kernel-trick" class="post-tag" title="show questions tagged &#39;kernel-trick&#39;" rel="tag">kernel-trick</a> will then hopefully pause after typing in "kernel", see two options, and hopefully read the tag summaries and pick the correct one.</p>

<p>I'm happy to do that sorting (a few at a time during low-traffic times).</p>
