Experimental Analysis of Behavior

Functional Analysis of Behavior

• Two ways to classify behavior:– Structurally:

• what are the components of the behavior; what is its structure?

• What is the topography of the behavior

– Functionally: • what is the function of the behavior? What is its

purpose?• What is the behavior gaining the organism?• What is the behavior’s reinforcement history/

Response Functions

• Think of behavior as a performance that follows a specific stimulus and results in a particular consequence:– S+: R C (Sr or P)

• Can analyze behavior using 3-step analysis:– ABC– A: antecedents: what are the setting conditions/stimuli– B: Behavior: what is the structure/topography of the response– C: Consequences: what reinforcer or punisher follows the behavior

• Determining the ABCs of behavior help determine the function of the response

But what is a Response?

• Response (R)= an integrated set of movements or a behavioral performance.

• Two classes of responses– Respondent– Operant

Functional Responses Classes

Response Class Function Controlling Event

Respondent ElicitedStimulus(event) preceding the response

Operant EmittedStimulus or event FOLLOWING the response

Responses

• Elicited Responses:– No consequence controls this behavior– Classical conditioning– Often reflexive or innate behaviors (but not always)

• Emitted Responses:– Operant behavior– Will have a reinforcement function (what does it get you?)– Discriminative function: Can come under discriminative

control by a discriminative stimulus or stimuli

Stimulus Classes• Stimuli have different functions, as well

– Defined by common effect on behavior– Not defined by the similarity of the stimuli, but on their FUNCTION

• Discriminative stimuli: – Serve as a cue for particular behaviors– Bring that behavior under stimulus control– E.g.: Stop signs result in a particular behavior

• Reinforcing stimuli– Again defined by their function, not their similarity– Here we get a four-square of behavior

• Reinforcement: positive and negative• Punishment: positive and negative

Motivation of Behavior• Context of behavior matters:

– Stop signs: • if walking, typically don’t STOP at a stop sign• Driving: do STOP at a stop sign• Using Normal Theater as lecture hall: any problems with context of behavior?

– Deals with setting conditions:– What conditions “set” the contingency?

• Establishing operation: EO: (Michael, 1982): any environmental change that has 2 major effects:

• Change increased the momentary effectiveness of reinforcement supporting operant behavior• Change increased momentarily the responses that had in the past produced such reinforcement

• Abolishing operation: AO: decreases momentary effectiveness of reinforcement and momentarily decreases rate of response

• Motivational operation (MO): any event that alters the reinforcement effectiveness of behavioral consequences and changes the frequency of the behavior maintained by those consequences

Conducting Behavioral Research from a Behaviorist Perspective

• Make use of basic tactics of research:– Independent variable– Dependent variable– Correlational research– But: use Single Subject Designs rather than group designs!

• Interested in behavior change in an individual– Use individual as own control– In ABA, important that behavior change is functional and clinically

significant– Allows evaluation of small groups and individuals– NOT interested in the mean, but in individual behavior change

Single- subject designs

• Single- subject designs: – Also called single- case designs– research designs that use the results from a single participant or

subject to establish the existence of cause- and- effect relationships.

• does not provide researchers with a set of scores from a group of subjects

• Instead: presentation and interpretation of results from a single- subject experiment are based on – visual inspection of a simple graph of the data– In experimental analysis, also statistical analysis

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Example

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Limitation

• The results as presented do not represent a true experiment because there is no control over extraneous variables.

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Phases and phase changes

• A phase: series of observations of the same individual under the same conditions.

• Baseline: observations when no treatment is being administered

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3 types of baseline

1. Stable level 2. Stable trend 3. Unstable data

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Dealing With Unstable Data

• The researcher can simply wait; occasionally, a participant reacts unpredictably to the novelty of being observed.

• Consider the average of a set of two (or more) observations.

• look for patterns within the inconsistency. – For example, a researcher examining disruptive classroom

behavior may find that a student exhibits very high levels of disruption on some days and very low levels on other days.

– E.g., days she has a swimming lesson14

Length of a Phase

• To establish a pattern ( level or trend) within a phase and to determine the stability of the data within a phase, a phase must consist of a minimum of three observations.

• Why? Three points make a line!– Allows you to (hopefully) determine the direction

of behavior change– May need more if data are unstable

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When to Change Phases• Wait:

• When the data in a baseline phase show a trend indicating improvement in the client’s behavior

• a researcher should not intervene by introducing a treatment phase.

• Don’t Wait: • If baseline data indicate a seriously high level of dangerous or threatening behavior. • Researcher probably should not wait for the full set of five or six observations

necessary to establish a clear pattern.

• Stopping Treatment: – If a treatment appears to produce an immediate and severe deterioration in

behavior, – Stop the treatment IMMEDIATELY

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Visual Inspection Techniques

• Unfortunately, there are no absolute, objective standards for determining how much of a change in pattern is sufficient to provide a convincing demonstration of a treatment effect.

• The most convincing results occur when the change in pattern is immediate and large.

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4 types of change• Change in average level:

– change in average baseline rate and average treatment rate

• Immediate change in level– Compare the last point in one phase with the first point in the

following phase

• Change in trend: – Compare the slope of the trend in baseline with the shape of the trend

in treatment

• Latency of change.– Compare the latency of change in baseline with latency of change in

treatment.

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2- immediate change in level

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Change in Trend

Latency in change

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The problem with single subject design:Need to find a way to show causation

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THE ABAB REVERSAL DESIGN

• the majority of single- subject research studies use ABAB design

• consists of four phases: – a baseline phase ( A)– followed by treatment ( B)– then a return to baseline ( A)– finally a repetition of the treatment phase ( B).

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Effective

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Not Effective

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Limitations of the ABAB Design

• The implemented treatment has corrected a problem behavior, and when the treatment is removed, the correction continues.

• A second problem with an ABAB design concerns the ethical question of withdrawing a successful treatment.

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Variations on the ABAB Design

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B not working, introduce C

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B not working add C

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B= Graduated exposureC= Reinforcement

MULTIPLE- BASELINE DESIGNS

• Uses multiple baselines and multiple interventions (hence the name!)– Across stimuli– Across environments– Across individuals– Across behaviors

• Eliminates the need for a return to baseline and therefore

• Is particularly well suited for evaluating treatments with long- lasting or permanent effects.

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2 different students 32

Person1

Person2

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Yelling

Crying

2 different behaviors

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School

2 different situations.

Home

Weaknesses of the Multiple- Baseline Design

• Risk that a treatment applied to one behavior may generalize and produce changes in the second behavior. • E.g., Treating stuttering may help treating aggressive behavior• Or: getting a great “down” for your dog results in loss of the “sit”• Solution: chart and monitor behavior change in both• This could be good OR bad change

• one behavior may show a large and immediate change, but the second behavior may show only a minor or gradual change when the treatment is introduced.• Floor and ceiling effects• Treatments may have different levels of effect on different behaviors• Can convert data to proportions to see if it is a measurement issue

• The same problem can occur with research involving different participants with similar behavior problems.

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Dismantling design

• Dismantling design– also called a component- analysis design– consists of a series of phases in which each phase

adds or subtracts one component of a complex treatment

– Allows one to determine how each component contributes to the overall treatment effectiveness.

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Example

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5- The Changing- Criterion Design

• The criterion level is changed from one phase to the next.

• Add to, take away or change criterion– E.g., out of seat behavior:• Phase 1: 5 out of seats/day• Phase 2: 3 out of seats/day• Phase 3: 1 out of seat/day

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Smoking Treatment

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The Alternating- Treatments Design

• Also called a discrete-trials design,

• Two ( or more) treatment conditions – randomly alternated from one observation to the

next.– No set schedule; subject doesn’t know which is

coming when

• E.g., scent enrichment in zoo animals40

Example 1- Alternate weeks

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Example 2- 9 cases for each method

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GENERAL STRENGTHS OF SINGLE- SUBJECT DESIGNS

• Conducted with only one participant or occasionally a very small (N~5) group.

• Tends to be much more flexible than a traditional group study.

• Single- subject designs require continuous assessment.

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General Weaknesses Of Single- Subject Designs

• Participant’s behavior may be affected not only by the treatment conditions but also by the assessment procedures.– Sometimes measuring behavior changes it– Draws attention to the behavior; subject alters behavior

• Another concern for single- subject designs can be absence of statistical controls.– Can address this with additional statistical measures designed for

behavior analysis– Typically included in EAB research; now seeing more and more in

ABA research44