">se.type =</span> <span class="st">"shade"</span>, 
      <span class="dt">draw =</span> <span class="st">"add"</span>)</code></pre></div>
<p><img src="Introduction_files/figure-html/unnamed-chunk-25-1.png" width="768"></p>
<p>Note, however, that interpreting these kind of continuous-by-continuous interaction terms is slightly more complex because the marginal effect of both constituent variables always depends on the level of the other variable. We’ll use the horsepower (<code>hp</code>) variable from <