16-01-2013, 01:22 PM
Single -Subject Designs
Single -Subject Designs.ppt (Size: 1.08 MB / Downloads: 243)
Big Idea: An array of ABA designs exists
Certain ABA designs (a.k.a. formats) can indicate experimentally to others ‘what is working’ in your classroom for your students.
Of all 6 designs, 3 do yield functional relationships (ABAB, Changing Criterion, and Multiple Baseline)
Of all 6 designs, 3 do not yield functional relationships (AB, Changing Conditions, and Alternating Treatment)
See glossary - p.425 for definition of functional relationship
See page 118 (‘Single-subject experimental designs allow…cause of the effects’) for explanation of functional relationships.
ABA - Baseline Requirements
In order to evaluate whether your instruction is achieving changes in your students’ school life, you should begin with a baseline.
Baseline data are measures of the level of behavior (recall the description of dependent variables) as it occurs naturally (prior to your intervention).
Certain rules govern the collection of valid baeline data.
Some Considerations
Simplicity
Cannot be used to establish functional relationship
Very vulnerable to confounding variables or coincidental events
See example on next slide.
3.Changing Criterion Design
Some Considerations
+Gradual acquisition may not be appropriate here
+Functional relationship is established (w. 3 successful phases)
+Continually progresses toward target behavior - no reversal
+Appropriate in ‘shaping’ behaviors
Requires setting interim and final goals
“After the student has reached the established level of performance in a predetermined number of consecutive sessions (usually 2, or in 2 out of three consecutive sessions of a subphase), the level of performance required for reinforcement should be adjusted in the direction of the desired level…Each successive interim level of performance should be determined using the same mathematical difference established at the first interim level of performance” (p. 131).