Quiz

1
Quiz

• Question In what way are fixed-ratio (FR) and
  variable-ratio (VR) reinforcement schedules
• similar?
• different?

2
Quiz

• Answer similar based on number of responses
• different fixed number fixed
• variable number varies

3
Have I witnessed a hurricane?

• Answer Heck yeah!

X
4
Reinforcement

• Definition
• A stimulus change
• contingent on some aspect of a response that
• increases the future probability of the response

5
Distinguishing Characteristics of Reinforcement

• Type
• Social
• Edible
• Tangible
• Reinforcement history
• Primary (unconditioned) reinforcer Reinforcer
  whose effects are not dependent upon prior
  learning
• Secondary (conditioned) reinforcer Reinforcer
  whose effects are acquired through pairing with
  other reinforcers

6
Determinants of Reinforcement Effects

• 1. Reinforcer Parameters
• Immediacy
• Contingency
• Magnitude
• Quality

7
Determinants of Reinforcement Effects

• 2. The Establishing Operation (EO)
• Antecedent event that
• Alters the effectiveness of a given reinforcer,
  and
• Increases the likelihood of behavior that has
  produced that form of reinforcement in the past
• Types of EOs
• Deprivation Typical EO for behavior maintained
  by Sr
• Aversive stimulation Typical EO for behavior
  maintained by Sr-

8
Schedules of Reinforcement

• Schedules of reinforcement determine the
  frequency and distribution of behavior in time
• Definition
• A formula (or rule) describing the probability
  that a given R will produce reinforcement or, a
  formula describing the proportion of Rs that will
  be reinforced
• Schedules are based on a continuum of probability
  values
• Contingency Schedule Probability of Sr
• Every R? Sr Continuous Sr (CRF) p 1.0
• No Rs ? Sr Extinction (EXT) p 0
• Some Rs ? Sr Intermittent Sr (INT) 0 lt p lt 1.0

9
Advantages of Intermittent Reinforcement

• Prevents satiation INT Sr maintains state of
  deprivation (EO)
• Resistance to EXT? INT Sr is less predictable
  than CRF therefore change to EXT more difficult
  to discriminate
• Can produce high rates of R (more Rs required for
  Sr)
• Naturalistic Most schedules in natural
  environment are INT
• Cost effective Easier for agent to administer

10
Basic Schedule Parameters

• Response requirement
• Ratio Sr based on number of Rs
• Interval Sr based on time elapsed since last
  reinforced R
• Regularity
• Fixed Requirement constant between Sr deliveries
• Variable Requirement changes from one Sr
  delivery to another

11
Basic Schedules of Reinforcement

• Ratio Interval
• ( of Rs) (Time since last reinforced R)
• Fixed
• (Requirement
• for Sr constant)
• Variable
• (Requirement
• for Sr changes)

Fixed Ratio (FR) (Sr delivered following fixed
of Rs)
Fixed Interval (FI) (Sr delivered for 1st R
after fixed amt of time since last reinforced R)
Variable Interval (VI) (Sr delivered for 1st R
after variable amt of time since last reinforced
R)
Variable Ratio (VR) (Sr delivered following
of Rs that varies around an average value)
12
Schedule Effects on Behavior

• Ratio Interval
• (High R rate) (Moderate R rate)
• Fixed
• (Irregular
• R rate)
• Variable
• (Stable R rate)

Fixed Ratio (FR) High, irregular rate (PRP, break
run)
Fixed Interval (FI) Moderate irregular rate (FI
scallop)
Variable Ratio (VR) High stable rate
Variable Interval (VI) Moderate stable rate
Real life examples?
13
Response Patterns Generated by Basic Schedules
Sr
Break Run
PRP
14
Response Patterns Generated by Basic Schedules
15
Response Patterns Generated by Basic Schedules
FI Scallop
Sr
16
Response Patterns Generated by Basic Schedules
17

Guess the Schedule!
18
How hard is graduate school?

• Answer pretty darn hard
• Answer but it also depends

19
Quiz 2

• Question

20
Activity 9/12

• Preference Assessment Methods to identify
  potential reinforcers
• Indirect checklists (RAISD, RAQ)
• Descriptive Premack
• Experimental Paired-stimulus Preference
  Assessment (Fisher et al. 1992)
• Reinforcer Assessment to validate reinforcement
  effects
• Practice various schedules