Which schedule provides reinforcement after the subject has maintained a behavior for a continuous period, such as staying for 2 minutes?

• A. Fixed Duration
• B. Variable Duration
• C. Fixed Ratio
• D. Variable Interval

Answer: (A)

The idea tested here is reinforcement that is tied to a fixed amount of time during which the behavior must continue. In a fixed duration schedule, you reinforce only after the subject has maintained the target behavior for a specific, unchanging length of time. So, if the rule is to reinforce after staying for 2 minutes, the reinforcement comes at the end of those 2 minutes as long as the behavior was continuous throughout the entire interval. This differs from a fixed ratio, which rewards after a set number of responses rather than a time period, and from interval schedules, which depend on time passing but not on sustaining the behavior for a continuous duration. A variable duration would require a changing amount of time, so it wouldn’t guarantee a 2-minute continuous period.