Performance Management: Changing Behavior That Drives Organizational Effectiveness (part 8)

Maintaining Performance Improvement: Schedules of Reinforcement

by

Charles Lamson

Interval schedules

1. Fixed interval

A fixed interval (FI) schedule is one in which a fixed amount of time must pass before a given behavior will be reinforced. There are two criteria for reinforcements on a fixed interval (FI) schedule. First, some period of time must go by before a reinforcer is delivered; and second, at the end of this period, the desired behavior must occur to produce the reinforcer.

Suppose you work in an area that is inspected for housekeeping on the last day of every month. The reinforcement may be positive in that you will be praised if it is good, or it may be negative in that the best you can hope for is to avoid a chewing out. The consequences will be delivered for having a clean area on that day. It does not matter whether you kept your area clean or messy during all the preceding days of the month. Reinforcement is available only on the last day.

Because it is a monthly inspection, the performance (housekeeping) will never be reinforced (inspected) during the interval no matter how often you do it - only at the end of the interval. But keep in mind that on interval schedules, reinforcement is not automatically given at the end of the interval. The performance must first occur. In this case, the place must be clean.

On an FI schedule, responding immediately after is never reinforced. This usually produces a distinctive performance pattern. Behavior under FI schedules is highly predictable. In the early part of the interval, the behavior increases, often dramatically.

This pattern, referred to as break and run, is generated because the response rate usually drops to zero following reinforcement but accelerates as the end of the interval approaches. This happens because behavior occurring immediately after reinforcement is never reinforced on an FI schedule and time discrimination is learned so that the performers can approximate when the end of the interval is near.

Figure 1 is a list of examples of FI schedules in everyday life.

Figure 1 Examples of Fixed Interval Schedules

2. Variable interval

A variable interval (VI) schedule is one in which the time between the opportunities for reinforcement varies. For example, the first time reinforcement is available may be after 1 hour, the next time may be 3 1/2 hours later, then again 22 minutes later, and finally, after only 8 more minutes. In this example, on the average, reinforcement is available every 75 minutes (VI 75), but the times it is actually available vary greatly. In other words, the performer never knows exactly when his behavior will be reinforced.

As with FI, the behavior must be occurring when reinforcement becomes available in order to get the reinforcer. Because the performer cannot predict whether any given response will be reinforced. VI offers a different performance pattern than FI.

On VI schedules, in contrast to FI schedules, reinforcement can follow reinforcement, therefore, reinforcers can be delivered close in time to each other. The behavior can be reinforced at any time, even if it was reinforced only minutes or seconds before. If the performer repeats the desired behavior, that behavior may or may not be reinforced, but he does not have to wait until a set period of time has elapsed as with FI schedules. A VI schedule produces a low-to-moderate, but very steady response rate.

VI schedules generate response rates exemplified by something like listening to the radio for your favorite songs to be played. You constantly monitor what is being played because you never know when you might hear an old favorite. Since on any VI schedule, the longer you wait the higher the probability of reinforcement, these schedules tend to produce patience. The result is clearly seen in those who fish off the end of a pier at the seashore. They never get in a hurry and are content to stay there for long periods of time, waiting for the fish to bite.

A nurse who checks the bulletin board to see the new work schedule also demonstrates an example of a VI schedule. Suppose the nursing supervisor posts the schedule at various times during the week, depending on her workload. The behavior being reinforced in this case is checking the bulletin board. The reinforcer is seeing her work schedule. No matter how frequently the nurse checks the board, the schedule will not be posted until the supervisor has completed it. In other words, the behavior of checking the bulletin board does not cause the work schedule to be posted. Throughout the week, the nurse will check the board from time to time because experience tells her sooner or later it will be posted.

Even though VI produces a relatively low rate of behavior, since it produces steady or regular responding, it is the most appropriate schedule for many jobs. For example, consider the case of a security guard patrolling an area. Her performance consists of physically checking various points along the route to make sure doors are locked, windows are latched, and lights are turned on or off as appropriate. We want her to ride or walk slowly through all the areas under surveillance. One of the primary values in her performance is to let any would-be intruders know that the area is always patrolled. We do not want her to hurry through the checkpoints.

We certainly do not want her to take a break after each patrol, and then rush through the round and complete the next one on time. That is, of course, what an FI schedule would produce. If she were required to make one check every hour, that is exactly the kind of performance you would predict. But on the proper VI schedule, where finding something wrong is the positive reinforcer, she would slowly and methodically go through her checkpoints and on returning to the security office, do any paperwork and resume her rounds. The chance of catching someone doing something wrong is increased by being in the area when someone attempts to steal, et cetera. Therefore, she maximizes her chances by spending time checking.

Variable interval schedules are appropriate for any job where patience or vigilance are more important than speed. In an age where more and more jobs require people to monitor TV or computer screens to detect certain errors or events, knowledge of how to properly apply VI schedules is important.

Figure 2 shows some examples of behaviors that are usually on VI schedules.

Examples of Variable Interval Schedules

*PERFORMANCE MANAGEMENT: CHANGING BEHAVIOR THAT DRIVES ORGANIZATIONAL EFFECTIVENESS, 4TH ED., 2004, AUBREY C. DANIELS & JAMES E. DANIELS, PGS. 81-84*

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