Why is perception hard?
Task: available signals → model of the world around
signals are mostly accidental, inadequate
sometimes disguised or falsified
always mixed-up and ambiguous
Reasoning about the source of signals:
Integration of context: what do you expect?
“Sensor fusion”: integration of vision, sound, smell etc.
Source (and noise) separation:
   there’s more than one thing out there
Variable perspective, source variation etc.
depends on the type of signal
depends on the type of object
Much harder than chess or calculus!