Variable Ratio Schedule
Description: A reinforcer is given after a specified number of correct responses.
This schedule is used to increase and maintain a steady rate of specific responses.
This schedule is best for maintaining a behavior.
- A high steady rate until reinforced
- No (or only a very small) pos-treinforcement pause.
- The value of a variable rate schedule can be increased a greater rate than
a fixed rate schedule without producing ratio strain, and
- A high RTE and the values of variable ratio that can maintain responding
are somewhat higher than those of a fixed ratio.
Examples in natural environments:
- Slot machines. Slot machines are programmed on VR schedule. The gambler
has no way of predicting how many times he must put a coin in the slot and
pull the lever to hit a payoff but the more times a coin is inserted the greater
the chance of a payout. People who play slot machines are often reluctant
to leave them, especially when they have had a large number of unreinforced
responses. They are concerned that someone else will win the moment they leave.
- Playing golf. It only takes a few good shots to encourage the player to
keep playing or play again. The player is uncertain how good each shot will
be, but the more often they play, the more likely they are to get a good shot.
- Door to door salesmen. It is uncertain how many houses they will have to
visit to make a sale, but the more houses they try, the more likely that they
Examples in video games
- Collecting tokens. Some games require the player to collect tokens to achieve
a life point or reward but vary the number of tokens required.
- Achieving a new level in an RPG. Some RPG's give no clear indication of
how much experience is required to achieve the next level. The puts the player
on a variable ratio schedule.
- Obtaining frags in an FPS. Many of your shots will fail and it is not certain
what the outcome of any particular shot will be. However, the more targets
you shoot at, the more likely you are to get a frag.
- Crafting in an RPG. It may take multiple attempts to succeed, or to gain
a new level, but the more you try, the more likely your behavior is to be