Lee loves his new on-demand cable TV service, which is desig…

Lee loves his new on-demand cable TV service, which is designed to let him view anything he wants at any time of the day.  Most of the time it works without trouble.  He makes a selection by highlighting a title with his remote and presses “enter”, and the selected movie or TV show plays immediately.  However, Lee finds that on some occasions, his selections do not play.  Making a selection by highlighting a title and pressing play is reinforced according to a(n) ____________ schedule.

After hearing the song “The Entertainer” playing on a loudsp…

After hearing the song “The Entertainer” playing on a loudspeaker outside her house, Susan immediately runs outside.  In the past, when “The Entertainer” was playing and she went outside the little truck selling frosted orange drinks would stop and she was able to purchase a frosted orange drink.  This is an example of: