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Mean = 13.25 = 83% 14.75 12 14.5 12 13 13.75 12.5 13.5 12.75 13 14.

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Presentation on theme: "Mean = 13.25 = 83% 14.75 12 14.5 12 13 13.75 12.5 13.5 12.75 13 14."— Presentation transcript:

1 Mean = = 83%

2 Schedules of Reinforcement Chapter 13

3 A schedule of reinforcement is a rule specifying… –the arrangement and response requirements for reinforcement –e.g., whether a reinforcer follows every behavior, every other behavior, etc. 2 Simple Schedules –Continuous Reinforcement (CRF; FR1) The reinforcer follows every behavior CRF results in rapid acquisition (good for teaching) CRF produces little resistance to extinction –Extinction (EXT) Discontinuation of a response-reinforcer contingency What’s a Schedule?

4 Some rather than all responses are reinforced Two main categories –Ratio schedules: the reinforcer is delivered after every X behaviors –Interval schedules: the FIRST behavior after X amount of time is reinforced Produces better resistance to extinction than CRF –Good for maintaining behavior Intermittent Reinforcement

5 2 Types: Fixed Ratio and Variable Ratio Fixed Ratio: the reinforcer is delivered after a fixed number of behaviors –Designation: FR 5 (every 5 th target response is reinforced) –Produces high-rate responding – why? –Produces a post-reinforcement pause (PRP) PRPs are proportional to the size of the ratio –e.g., piecework Ratio Schedules

6 Fixed-Ratio Schedule of Reinforcement S R+ delivered PRP

7 Variable Ratio The reinforcer is delivered after an average number of behaviors Designation: VR 5 –5, 4, 7, 6, 4, 3, 6, 7, 3 Produces consistent, high rates with no PRPs e.g., starting a lawn mower Clinical applications…

8 Tic-Tac-Toe VR Procedure Teacher picks maximum number of responses for an individual or group (e.g., 30) –The smaller the #, the more likely it is that the learner(s) will meet the contingency Learners fill in each square of tic-tac-toe grid with a # no greater than the max Teacher fills box with numbers on slips of paper –Each number several times Contingent on target behavior, student picks slip of paper –If on tic-tac-toe, cross out number Deliver S R+ when 3 in a row

9 Classroom Lottery VR Procedure Students write their names on index cards after successfully completing assigned tasks –Cards go in a box After a preset period of time (e.g., 1 week),… –Teacher picks a card – that student is the winner –The more cards earned, the more likely a student will be the winner Reggie Lottery Box!

10 Both FR and VR schedules have 2 major advantages –Produce high rates of responding –Easy to use Potential Disadvantage –Ratio strain can result from abrupt increases in ratio requirements Considerations with Ratio Schedules

11 2 Types: Fixed Interval and Variable Interval Fixed Interval: the reinforcer is delivered for the first target response after a fixed period of time has elapsed –Designation: FI 60s –e.g., turning on the TV to watch your favorite show –Characteristics Produces PRPs, resulting in scallop or break-and-run patterns Slow to moderate rate of responding Interval Schedules

12 S R delivered PRP

13 the reinforcer is delivered for the first behavior after an average period of time has elapsed –Designation: VI 60s –produces steady, moderate responding (no PRPs) –e.g., checking Limited Hold: a feature that can be added to any interval schedule –The behavior must occur after the interval has elapsed, but within a specific period of time –Designation: FI 5 min LH 30 s Variable Interval Schedule

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15 Use if you want to produce low to moderate response rates Advantage –FI schedules are relatively easy to use with a resetting timer Potential Disadvantage –Off-task or other unwanted behavior may occur during the PRP Considerations with Interval Schedules

16 Post-reinforcement pause FI scallop time # responses

17 Schedule thinning: Gradually increasing the response ratio or the extent of the time interval Benefits –The student’s behavior becomes more durable (more resistant to extinction) –More practical for caregivers to implement If you move too quickly, you can produce ratio strain –Aggression –Extinction of responding Not many guidelines are available to tell us how to do this Thinning the Schedule of Reinforcement

18 LeBlanc, Hagopian, Maglieri, & Poling (2002) Determine a reasonable terminal goal that’s appropriate to the age and functioning level of the learner Establish a series of steps between the initial value and the terminal value –8-12 steps are recommended –Increase 33% to 50% at each step Stay at one step at least 2 times If student is unsuccessful, go back a step Periodically probe a few steps ahead

19 LeBlanc et al.: Thinning from FR1 1FR2100% 2FR4100% 3FR650% 4FR950% 5FR1233% 6FR1633% 7FR2133% 8FR2833%

20 Differential Reinforcement of Rates of Responding DRH: Reinforcement of responses higher than a predetermined criterion (to produce a higher rate of responding) DRL: Reinforcement of responses lower than a predetermined criterion (to produce a lower rate of responding) 3 Types –Spaced-responding: reinforcement is only available for responses separated by a given duration of time (IRT) Not used much b/c it’s difficult to calculate IRT –Full session: reinforcement is delivered at the end of the session if the total number of responses during the session was less than or more than a criterion –Interval: Total session is divided into equal intervals and reinforcement is delivered at the end of each interval in which the number of responses was less than or more than a criterion

21 Compound Schedules of Reinforcement Combine different types of schedules Concurrent Schedules Discriminative Schedules –Multiple Schedules –Chained Schedules Nondiscriminative Schedules –Mixed Schedules –Tandem Schedules

22 Concurrent Schedules 2 or more contingencies of reinforcement operate independently and at the same time for 2 or more behaviors Used for –Reinforcer Assessments –Intervention Assessments Hanley et al. (2005) allowed individuals to choose which intervention they preferred –FCT + Punishment was preferred to FCT + Extinction –Interventions Hoch et al. (2002) – boys with autism could play alone or with sibling –Sibling was chosen when SR magnitude and quality were increased Use this when you can’t or shouldn’t treat inappropriate behavior directly

23 Multiple Schedule A type of discriminative schedule Two or more schedules are presented one after another –Each is correlated with a discriminative stimulus Tiger and Hanley (2004) –Different colored leis worn by the teacher were S D s correlated with schedules of reinforcement for attention

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25 FR1 Component (S D )

26 EXT Component (S ∆ )

27 Minimum response criterion 15 s – 270 s5s–1s1 s – 60 s

28 Chained Schedule A type of discriminative schedule Differs from multiple schedule: –Schedules in the chain occur in the same order –Behavior may be the same or different for each component of the chain –Conditioned reinforcement for the first element of the chain is presentation of the second element The last response is reinforced with most powerful reinforcer

29 Nondiscriminative Schedules Mixed (like multiple schedule without the SDs) –Tiger and Hanley (2004) – conducted the same sessions without the teacher wearing leis Tandem (like chained with out the SDs)

30 Use Caution… When extrapolating information about schedules from basic research to applied settings –Most applications of schedules only approximate lab schedules –Many uncontrolled variables in applied settings will influence a person’s sensitivity and insensitivity to a schedule of reinforcement


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