B. F. Skinner discovered that WHEN you reinforce a behavior has a lot to do with what type of behavior you get. He wrote about "Schedules of Reinforcement" ... which is exactly as it says...a description of the schedule you use to reinforce (reward) behavior. You may reward a behavior continuously ... every time it occurs..or you may use intermittent ( or partial ) reinforcement..which means you don't reward the behavior every time it happens. Continuous reinforcement is good to get a behavior started..but in almost all cases you need to switch over to intermittent once the person (or animal) starts doing what you want it to do. There are 4 types of Intermittent or Partial Schedules of Reinforcement: Fixed ratio, variable ratio, fixed interval, and variable interval. If you know what these four words mean: Fixed (same), Variable (changes), Ratio (Numbers) and Interval (Time)..then you can figure out any problem with Schedules of Reinforcement...and there are several on the test. Examples of each: Fixed ratio--- payment by commision; frequent flyer miles, subway punch card (every 10 subs, earns you a free sub--- the reward). Variable ratio--- slot machines, playing the lottery, sales. Fixed interval--salaried jobs (paid every two weeks, once a month, etc.), drug tests at the beginning of a season, before the Olympics, quarter grades, etc. Variable interval--- fire drills, random drug testing, natural disasters, musical chairs, etc.