<p>I've created tag <a href="https://stats.stackexchange.com/questions/tagged/mixed-data" class="post-tag" title="show questions tagged &#39;mixed-data&#39;" rel="tag">mixed-data</a>. I mean a mixture of variables of different types or scales.</p>

<p>We long have tags <code>[continuous-data]</code>, <code>[categorical-data]</code>, <code>[binary-data]</code>, <code>[count-data]</code>, <code>[ordinal-data]</code>. All of them are necessary and should exist, to me. (We also have tag <code>[nominal]</code> and I wonder shouldn't it be kept, dismissed or merged to <code>[categorical-data]</code>.)</p>

<p>I think that we do need tag <code>[mixed-data]</code>. In many analyses, mostly multivariate exploratory methods (cluster, factor, irt,...), but also in other as well, mixing variables of different types in one set represent a special problem to solve.</p>

<p>I want therefore to ask you some questions:</p>

<ol>
<li>Do we need that tag?</li>
<li>Shall it be worded <code>[mixed-data]</code> or
<code>[mixed-type-data]</code>?</li>
<li>Shall we narrow the definition - in the excerpt - so that we don't include the (very usual) case of using mixed type predictors (continuous+categorical) in regression-like modeling in the concept of "mixed data", or include that case in the concept too - along with using mixed data in clustering, PCA, etc.?</li>
<li>Other thoughts from you, please welcome.</li>
</ol>
