tion encoding="application/x-tex">S</annotation></semantics></math>
and to the method that attributes variation in richness to particular
observers.</p>
<p>Prior to Version 2022, predictive features comprised weather,
landcover, habitat diversity, protocol, day of year, and variables that
are particular to the observer: observer_id and checklist_number (i.e.,
index of how many checklists a user has ever submitted from any stixel
to eBird; not to be confused with checklist_id). A mixed-effects
generalized ad