<p>I was trying to collate some tags about randomization and noted that <a href="https://stats.stackexchange.com/questions/tagged/random-allocation" class="post-tag" title="show questions tagged &#39;random-allocation&#39;" rel="tag">random-allocation</a> seemed to be the parent-tag of preference. As I searched tags for instances of "random" I noted some hits for <a href="https://stats.stackexchange.com/questions/tagged/randomized-experiment" class="post-tag" title="show questions tagged &#39;randomized-experiment&#39;" rel="tag">randomized-experiment</a>. I was about to propose the tag as a synonym, but noted that it was already merged into <a href="https://stats.stackexchange.com/questions/tagged/random-allocation" class="post-tag" title="show questions tagged &#39;random-allocation&#39;" rel="tag">random-allocation</a>. When I navigate to the questions tagged as such, the excerpt, wiki, and related questions are all those of <a href="https://stats.stackexchange.com/questions/tagged/random-allocation" class="post-tag" title="show questions tagged &#39;random-allocation&#39;" rel="tag">random-allocation</a>. </p>

<p>So it prompts the question: why do tag synonyms show up in a search?</p>
