<p>I don't really agree here. <a href="http://en.wikipedia.org/wiki/A/B_testing" rel="nofollow noreferrer">A/B testing</a> is a specific kind of experimental design that is important and common in a specific setting (most typically website development, I gather).  It could be a duplicate for <a href="https://stats.stackexchange.com/questions/tagged/experimental-design" class="post-tag" title="show questions tagged &#39;experimental-design&#39;" rel="tag">experimental-design</a>, but I don't think it's a duplicate of <code>[hypothesis-testing]</code>.  Moreover, I think it is specific enough, and used often enough, to merit its own tag; we do have tags for other specific designs (e.g., <a href="https://stats.stackexchange.com/questions/tagged/split-plot" class="post-tag" title="show questions tagged &#39;split-plot&#39;" rel="tag">split-plot</a>).  </p>
