radiation coming from sources other than those being observed
a person's social heritage: previous experience or training
information that is essential to understanding a situation or problem
relatively unimportant or inconspicuous accompanying situation
extraneous signals that can be confused with the phenomenon to be observed or measured
the state of the environment in which a situation exists
(computer science) the area of the screen in graphical user interfaces against which icons and windows appear
energy that is radiated or transmitted in the form of rays or waves or particles
the act of spreading outward from a central source
