Relating probability amplitude mechanics to standard statistical models

The probabilities assessed for an event by a more detailed experiment (e.g., one which measures both a particle's position on a detection screen and which of several slits it traversed to reach that screen) may differ from the probabilities assessed for that same event by a less detailed experiment (e.g., one which only measures the particle's position on the detection screen.) As this paper shows, probability amplitude mechanics writes the detailed experiment probabilities as a weighted average of the less detailed experiment probabilities and some factor measuring the variability overlooked by the less detailed experiment. (orig.)