ion performs with more or less historical data.</p>
</section>
<section id="approximate-cross-validation" class="level3 unnumbered">
<h3 class="unnumbered anchored" data-anchor-id="approximate-cross-validation">Approximate cross-validation</h3>
<p><span class="citation" data-cites="VehtariEtAl:2017">Vehtari, Gelman, and Gabry (<a href="#ref-VehtariEtAl:2017" role="doc-biblioref">2017</a>)</span> introduce a method that approximates the evaluation of leave-one-out cross validation inexpensively using only th