an be avoided by naming the new variable the same as the old</span></span></span>
<span class="r-in"><span><span class="co"># variable)</span></span></span>
<span class="r-in"><span><span class="va">oTree</span><span class="op">$</span><span class="va">survey</span><span class="op">$</span><span class="va">gender</span></span></span>
<span class="r-out co"><span class="r-pr">#&gt;</span>  [1] "Male"   "Female" "Male"   "Female" "Female" "Male"   ""       "Male"  </span>
<span class="r-out co"><span class="r