how do you know it worked
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How do you know it worked. Single Subject Designs in Teaching. How do we know if our teaching is successful or change is due to chance?. Functional Relationship – a cause and effect. The target behavior changes as a result of the intervention - PowerPoint PPT PresentationTRANSCRIPT
How do we know if our teaching is successful or change is due to chance?
Functional Relationship – a cause and effect. The target behavior changes as a result of the intervention
Functional Relationship exists between the two variables when the interventions have been systematically replicated on or more times
Variable: any number of factors involved in research. (factors related to participants, conditions, interventions)
GOAL: to control for the presence of absence of variables that may effect the outcomes
Variables
Independent: intervention being used
Dependent: behavior targeted for change
Confounding: Those variables in the environment that are not controlled but may influence the dependent variable
Components of a SSD
Baseline Measures A measure of the behavior under the
conditions that currently exist.
Provide a measure of the behavior if no intervention occurs.
Components of a SSD
Baseline Measures Why do we want a baseline to be as
stable as possible?
What are two measures of stability?VariabilityTrend
What to consider when trying to intervene?
Too much variability makes it difficult to draw conclusions
Good operational definition of the dependent variable
Naturally occurring variability
Components of a SSD
Intervention Measures Repeated measures of the behavior
under treatment conditions
Experimental Control insures that changes in the behavior are in fact due to the intervention and not other confounding variables…a functional relationship exists
Teaching designs
A functional relationship is not established (lack of experimental control)
Less confident assumptions can be drawn
Provide sufficient indication of behavior change
AB Designs
Referred to as the “Teaching design”
Consists of two phases
Data collected during intervention are compared to those collected during baseline
Advantages Disadvantages
Simple to use
Compares student performance
Cannot make confident assumptions
Good to graph acquisition obj.
Reversal Designs
Used to study the effectiveness of a single intervention (independent variable)
Consists of 4 phases Should not be used:
When dependent variable is dangerous
When dependent variable is not reversible
Advantages Disadvantages
Experimental control
Must withdraw intervention
Simple
What problems does this pose?
Reversal Designs
Repeatedly compares baseline data to intervention data
Dependent on the replication of baseline and intervention effects
Confounding variables?
Changing Criterion Design
Evaluates the one independent variable on one dependent variable
Experimental control is demonstrated by incrementally increasing or decreasing the dependent variable
Consists of two phases
Advantages Disadvantages
Functional relationship without withdrawing intervention
Must be used on behaviors that require small incremental changes
Progress oriented
Starting with small change
Changing Criterion Design
Implementation Collect baseline data Determine interim criterion for
performanceMean of the stable portion of baselineHalf the mean of the baselineHighest or lowest baseline Professional estimate
Changing Criterion Design
Demonstrating Functional Relationship Alter the number of sessions Continue with a sub-phase until a
stable rate Vary the increase Require a change in the opposite
direction
Multiple Baseline Designs
Analysis of 1 independent variable on more than 1 dependent variablesAcross behaviorsAcross settingsAcross individuals
Consists of 2 phases
Multiple Baseline Designs
Cannot be used with a behavior that calls for immediate action
When behaviors are not independent
Advantages Disadvantages
Establish a functional relationship (without reversing the intervention
Must implement across settings, people, etc. -- cumbersome
Allows the examination of one intervention on many kids
Collect baseline over extended period of time
Multiple Baseline Designs
ImplementationBaseline is collected on all conditions at the
same timeBegin intervention in first condition when
stable baseline is reachedBegin intervention in second condition when
change has occurred in the first condition
Multiple Baseline Designs
Extended BaselinesNot appropriate for some behaviorsKids may learn error responseKids may become frustratedNo instruction being delivered
Alternating Treatments Designs
Allows the comparison of the effectiveness of more than one intervention on a single dependent variable
Advantages Disadvantages
Efficient for teachers
Must implement a replication phase for functional relationship
Multiple treatment spillover
Alternating Treatments Designs
ImplementationEach condition equal number of timesSchedule of interventions should be
counterbalanced (to avoid order effects)Distinctive discriminative stimulus should
immediately precede the condition
Changing Condition Design
Implementation Interventions are introduced
sequentially. Functional relationship only if a return
to baseline occurs before C condition
Used to study the effectiveness of two or more treatments on the behavior of a student. ABC design
Advantages Disadvantages
Compare interventions
No functional relationship can be established
Cummulative effects