Recall that Reinforcement increases the likelihood that the proceeding behavior will increase. This can happen differently based on how often (interval) and how frequent (ratio) reinforcement is received. Both interval and ratio can be fixed (same time/amount) or variable (different time/amount). This is referred to as schedules of reinforcement.

This leads to four possibilities. The following list contains all four possibilities and gives examples:

  • Fixed Interval: Reinforced after predictable intervals of time.
    • Example: getting paid for work after every two weeks. 
  • Variable Interval: Reinforced after unpredictable intervals of time.
    • Example: getting random emails/text messages.
  • Fixed Ratio: Reinforced after predictable number of responses.
    • Example: receiving a commission after every sale is made.
  • Variable Ratio: Reinforced after unpredictable number of responses. 
    • Example:  a slot machine that pays after a random number of spins.

Variable Ratio has the highest and steadiest response rate. This is one of the reasons why gambling is so addictive. If you are getting rewarded randomly, you’re more likely to continue with the behavior.

Fixed Interval has the lowest response rate and productivity.