2. The way researchers arrange comparisons between conditions
***Goal: Compare effects of independent variable on responding
Discover something from nature All experiments in Applied Behavior
Analysis include: Participant(s) Dependent variable(s) Setting(s)
Measurement system Independent variable(s) Experimental design
Experimental question
3. Experimental Designs How will comparisons be made? Between
Group Within Group Results in very different pictures of target
behavior Most fundamental decision which design?
4. Pool of participants is randomly chosen Participants are
randomly divided into 2 groups Pretest of dependent variable Mean
and standard deviation (pretest) are calculated for each group
Group 1: exposed to a control condition Group 2: exposed to an
experimental condition Posttest measure of dependent variable Mean
and standard deviation (posttest) are calculated for each group
Researchers compare changes in each groups scores
5. Assess the total effect of an independent variable on a
group of participants No individual behavior is analyzed Group data
may not represent any individual participants responding Group data
hides variability in the data Unable to replicate effects of
individuals ***When group data do not represent individual
responding, individual data should be included as well
6. Within Group Design Single-Subject Single-Case
Within-Subject Intra-subject Skinner: Behavior of individuals
organisms Antecedent and consequent events One or a few non-human
subjects Frequency of performance measured First used in basic
research studies and later extended to human behavior in applied
settings!
7. One or more participants are selected Each participant
serves as his or her own control Each participant is exposed to
control and experimental conditions ***continuous assessment Data
is graphed separately for each participant Responding is compared
across conditions Treatment effects are analyzed Within Group
Design
8. Primary area for study Identifying causes of behavior change
***treatment packages that improve socially significant behavior
Identifying learning techniques ***reinforcement, practice,
acquisition, extinction Comparing teaching methodologies
9. Experimental Designs Why choose within group design?
Behavior is characteristic of individual organisms No 2 individuals
behave just alike Description of an individual's responding differs
than a description of the combined behavior of multiple individuals
Average outcome effects differ from actual individual effects If
performance results are combined, results may not accurately
represent performance from any single participant . If performance
is recorded separately for each individual, then individual results
can be compared across conditions and analyzed
10. References Cooper, J. O., Heron, T. E., & Heward, W. L.
(2007). Applied Behavior Analysis (2nd ed.). Upper Saddle River,
NJ: Pearson. Johnston, J.M. & Pennypacker, H.S. (2009).
Strategies and Tactics of Behavioral Research (3rd ed.). New York,
NY: Routledge. Kazdin A.e. (2011). Single-Case Research Designs:
Methods for Clinical and Applied Settings (2nd ed.). New York, NY:
Oxford. Shabani, D.B. & Yan Lam, W. (2013). A review of
comparison studies in applied behavior analysis. Behavioral
Interventions, 28(2), 158-183.
