<p>I also don't see the distinction in those questions.  <code>graphical-techniques</code> just makes me think of <a href="http://en.wikipedia.org/wiki/Graphical_models" rel="nofollow">graphical models</a> (for which we do have a tag), so perhaps removing it and having only <code>data-visualization</code> would be best.</p>

<p>The only disadvantage of that is that when people have questions about plots, they're likely to try to tag it by typing "plot" or "graph" and hoping for an auto-complete; <code>data-visualization</code> won't be of much use there.  Now, if we could get "plot" and "graph" to autocomplete to <code>data-visualization</code>, we'd be set.</p>
