math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><semantics><msub><mi>p</mi><mi>i</mi></msub><annotation encoding="application/x-tex">p_{i}</annotation></semantics></math>
of
<math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mi>S</mi><annotation encoding="application/x-tex">S</annotation></semantics></math>
to data representing a “standardized search”, in which all features
except <code>observer_id</code> and <code>checklist_number</code> were
held constant (a