For each acquired window, an expert evaluated the quality of the window. The window was rated as "excellent, fair, poor, or other." "Other" captured situations where the window acquired was nondiagnostic. Window quality was dichotomized into two categories, "excellent or not excellent," and subsequent analyses examined the number of participants that acquired "excellent" windows by quadrant (perihepatic space (also called Morison's pouch or the hepatorenal recess), perisplenic space, pericardium, and the pelvis and suprapubic quadrant) and patient type (normal, positive).

For each acquired window, the participant rendered a diagnosis of that window. An expert evaluated the quality of the diagnosis. The diagnosis was rated as "correct, incorrect, or other." "Other" captured situations where the window acquired was nondiagnostic. For analysis purposes, diagnostic accuracy was dichotomized into two categories, "correct or not correct," and subsequent analyses examined the number of participants that interpreted the window correctly by quadrant (perihepatic space (also called Morison's pouch or the hepatorenal recess), perisplenic space, pericardium, and the pelvis and suprapubic quadrant) and patient type (normal, positive).