<p>I find there are <a href="https://stats.stackexchange.com/search?q=is%3Aquestion%20sets%20closed%3Ano%20-%22data%20set%22">some questions</a> about sets, but there isn't any tag about it.</p>

<p>I would like to ask questions about them and learn more about them. Thus I thought about creating a new <a href="https://stats.stackexchange.com/questions/tagged/set" class="post-tag" title="show questions tagged &#39;set&#39;" rel="tag">set</a> tag to group the questions. </p>

<p>Currently most questions I see are about different similarity metrics between sets or about rank based analysis of sets like gene set enrichment analysis.</p>

<p>Proposed tag wiki excerpt:</p>

<blockquote>
  <p>For questions about analysis of groups of nominal variables</p>
</blockquote>

<p>Prototype of a full tag wiki :</p>

<blockquote>
  <p>A set (See <a href="https://en.wikipedia.org/wiki/Set_(mathematics)" rel="nofollow noreferrer">definition</a>) can be defined as a group of elements:<br>
  set1 = element1, element2, element3<br>
  Questions might be about similarity indices, or analysis on them.</p>
</blockquote>

<p>PS: Are here some knowledge on operations and tests?</p>
