Transcript Chapter 7 Analyzing Behavior Change

Chapter 7:
Analyzing Behavior Change:
Basic Assumptions and
Strategies
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Concepts & Assumptions
Underlying the Analysis of Behavior
•
•
•
•
•
Determinism
Empiricism
Experimentation
Parsimony
Philosophic doubt
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Concepts & Assumptions
Underlying the Analysis of Behavior
“The overall goal of science is to achieve an
understanding of the phenomena under
study”
In applied behavior analysis – the
phenomena of interest is socially
significant behavior
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Concepts & Assumptions
Underlying the Analysis of Behavior
• Science enables various degrees of
understanding at three levels
– Description
– Prediction
– Control
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Experimental Control:
The Path to and Goal of Behavior Analysis
• Experimental control (defined)
– A predictable change in behavior (dependent
variable) can be reliably produced by the
systematic manipulation of some aspect of
the person’s environment (independent
variable)
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Experimental Control:
The Path to and Goal of Behavior Analysis
• Experimental analysis (defined)
– Experimentally determining the effects of
environmental manipulation on behavior and
demonstrating that those effects can be
reliably produced
– Can be achieved when
• A reliable functional relation between behavior and
some specified aspect of the environment has
been demonstrated convincingly
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Experimental Control:
The Path to and Goal of Behavior Analysis
• Internal validity
– The extent to which an experiment shows
convincingly that changes in behavior are a
function of the independent variable and not
the result of uncontrolled or unknown
variables
– Studies without high a high degree of internal
validity
• Yield no meaningful statements about functional
relations
• Lack generality
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Experimental Control:
The Path to and Goal of Behavior Analysis
• Confounding variables are those variables
known or suspected to exert an
uncontrolled influence on the dependent
variable
• The effects of confounding variables must
be evaluated and eliminated to
demonstrate experimental control
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Experimental Control:
The Path to and Goal of Behavior Analysis
“ the goal of experimental design is to
eliminate as many uncontrolled
variables as possible and to hold
constant the influence of all other
variables except the independent
variable, which is purposefully
manipulated to determine its effects”
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Behavior
Defining Features and Assumptions that Guide Its Analysis
• Defining features
– Behavior is an individual phenomenon
– Behavior is a continuous phenomenon
• Assumptions
– Behavior is determined
– Behavioral variability is extrinsic to the
organism
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Behavior
Defining Features and Assumptions that Guide Its Analysis
• Behavior is an individual phenomenon
– Behavior
• a person’s interaction with the environment
– Groups of people do not behave
• Experimental strategy of ABA is based on
within-subject (single-subject) methods of
analysis
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Behavior
Defining Features and Assumptions that Guide Its Analysis
• Behavior is a dynamic, continuous
phenomenon
– Changes over time
– Requires continuous measurement over time
• Complete record of behavior as it occurs in context
• Systematic repeated measurement is the
“hallmark” of ABA
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Behavior
Defining Features and Assumptions that Guide Its Analysis
• Behavior is determined
– The occurrence of any event is determined by
the functional relations it holds to other events
– Behavior is a natural phenomenon
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Behavior
Defining Features and Assumptions that Guide Its Analysis
• Behavioral variability is extrinsic to the
organism
– Variability is the result of environmental
influence such as,
• The independent variable under investigation
• Some uncontrolled aspect of the experiment
• Uncontrolled or unknown factor outside of the
experiment
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Behavioral Variability
Most commonly held assumptions in psychology
and other social/behavioral sciences
• The assumption of intrinsic variability
– An intrinsic characteristic of the organism
– Distributed randomly among individuals in any given
population
• Methodological implications
– Attempting to experimentally control or investigate
variability is a waste of time
– By averaging the performance of individual subjects
within large groups – the random nature of variability
can be statistically controlled or cancelled out
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Behavioral Variability
Assumptions of Behavior Analysts
• Behavioral variability is the result of an
environmental influence
• Methodological implications
– Experimental manipulations of the factors suspected
of causing variability
– Search for causal factors
• In practice
– Applied behavior analysts seek treatment variables
robust enough to overcome variability
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Components of Experiments in ABA
• At least one
–
–
–
–
Subject or participant
Behavior (dependent variable)
Setting
Treatment or intervention condition (independent
variable)
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Components of Experiments in ABA
(continued)
• A system for measuring the behavior and
ongoing analysis of the data
• Manipulations of the independent variable
so that its effects on the dependent
variable, if any, can be detected
– Experimental design
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Components of Experiments in ABA
(continued)
• Research question
– “a brief but specific statement of what the researcher
wants to learn from conducting the experiment”
(Johnston & Pennypacker, 1993b, p.366)
– What are the effects of the independent variable on
the dependent variable
• for what population & in what setting?
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Components of Experiments in ABA
(continued)
• Subject (s)
– In single-subject research the subject is employed as
his or her own control
• Measures of the subject’s behavior during each phase of the
study provide the basis for comparing experimental variables
as they are presented or withdrawn in subsequent conditions
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Components of Experiments in ABA
(continued)
• Behavior (s)
– Dependent variable (s)
• Reasons for multiple dependent measures
– Provide data patterns that can serve as controls for evaluating &
replicating the effects of an independent variable
– Assess the presence and the extent of the independent
variable’s effects on behaviors other than the response class to
which it was directly applied
– Determine whether changes in the behavior of a person other
than the subject occur during the course of an experiment & if
such changes can explain changes in the subject’s behavior
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Components of Experiments in ABA
(continued)
• Setting
“Control the environment and you will see order in behavior.”
(Skinner, 1967, p. 399)
• Control two sets of environmental variables to
demonstrate experimental control
– Independent variable
• Presenting, withdrawing, or varying its value
– Extraneous variables
• Prevent unplanned environmental variation
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Measurement System and
Ongoing Visual Analysis
• Observation & recording procedures must be
conducted in a standardized manner
• Standardization involves every aspect of the
measurement system
– Definition of the target behavior to scheduling of
observations
• Behavior analysts must develop skills in the
detection of changes in the level, trend, and
degree of variability in behavioral data
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Intervention or Treatment:
Independent Variable
• Independent variable (defined)
– The particular aspect of the environment that the
experimenter manipulates to find out whether the it
affects the subject’s behavior
– The researcher controls or manipulates this variable
independent of the subject’s behavior or any other
event
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Experimental design
Defined
• The particular arrangement of conditions in a
study so that meaningful comparisons of the
effects of the presence and absence of the
independent variable can be made
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Experimental design
• Nonparametric study
– Independent variable is either presented or absent
during a time period or phase of the study
• Parametric study
– The value of the independent variable is manipulated
– Seeks to discover the differential effects of a range of
values
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Fundamental Rule
• Change only one variable at a time
– Experimenter can attribute any measured changes to
a specific independent variable
– If investigating the effects of a “treatment package”
• Ensure that the entire package is presented or withdrawn
each time a manipulation occurs
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Some Additional Rules
• Do not get locked into textbook “designs”
– Often require a priori assumptions about the nature of
the functional relations one seeks to investigate
– May be insensitive to unanticipated changes in
behavior
• Select & combine experimental tactics that best
fit the research questions
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Steady State Strategy &
Baseline Logic
• “A pattern of responding that exhibits relatively
little variation in its measured dimensional
quantities over a period of time”
(Johnston & Pennypacker, 1993a, p. 199)
• Provides the basis for baseline logic
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Steady State Strategy &
Baseline Logic
• Steady state strategy
– Repeated exposure of a given subject to a given
condition while trying to eliminate or control
extraneous influences on behavior & obtaining a
stable pattern of responding before introducing the
next condition
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Steady State Strategy &
Baseline Logic
• Baseline logic
– Prediction
– Verification
– Replication
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Nature & Function of Baseline Data
• Serves as a control condition
• Does not imply the absence of intervention
– Absence of a specific independent variable
• Why?
– To establish a baseline level of responding to use
the subject’s performance in the absence of the
independent variable as an objective basis for
detecting change
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Nature & Function of Baseline Data
• Applied Benefits of establishing a baseline
level of responding
– To obtain descriptions of antecedent-behaviorconsequent correlations for the planning of an
effective treatment
– Valuable guidance in setting initial criteria for
reinforcement
– Baseline data may reveal the behavior targeted for
change does not warrant intervention
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Types of Baseline Data Patterns
• Stable baseline (A)
• Ascending baseline (B and C)
• Variable baseline (D)
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Types of Baseline Data Patterns
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Prediction
“the anticipated outcome of a presently
known or future measurement. It is the
most elegant use of quantification upon
which validation of all scientific and
technological activity rests.”
(Johnston & Pennypacker, 1980)
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Prediction
• Prediction
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Affirmation of the consequent
• Affirmation of the consequent
– Inductive logic
• “if the independent variable were not applied, the
behavior, as indicated by the baseline data path,
would not change
• If-A-then-B statement
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Affirmation of the consequent
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Verification
• Verification of a previously predicted level
of baseline responding by termination or
withdrawal of the treatment variable
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Verification
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Replication
“Replication is the essence of believability”
(Baer, Wolf, & Risley, 1968, p. 95)
• Replication of the experimental effect
accomplished by reintroducing the
treatment variable
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Replication
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved