PSYC3450 EXPERIMENTAL PSYCHOLOGY

1. PSYC3450 EXPERIMENTAL PSYCHOLOGY

2. Single-Subject / Small N Designs CHAPTER 11 Lecture Outline The Beginnings of Psychology Research Reasons for Small N Designs Applied Behavior Analysis (ABA) Case Study Designs

3. THE BEGINNINGS OF PSYCHOLOGY RESEARCH Most early research in Psychology… • Small N • Data not summarized; data for each subject presented • Additional subjects used for replication • Dresslar’s facial vision study (1892) • falsification thinking

4. REASONS FOR SMALL N DESIGNS Misleading results from statistical summaries of grouped data • A failure of individual-subject validity (e.g. discrimination learning research in children) • Grouped data  suggested gradual learning • Individual data  suggested hypothesis testing and quick solutions once proper hypothesis found • Solution: children reach criterion at different rates Continuity theory Non-continuity theory Practical problems with large N designs • Participants with a particular attribute are rare • E.g. OCD occurs in <2% of the population • Members of a specific animal species are rare, costly, or require too much time for training

5. THE EXPERIMENTAL ANALYSIS OF BEHAVIOR Operant Conditioning • Behavior conditioned in a particular environment by consequences (e.g. reinforcement) • Primary DV  rate of response • Recorded cumulatively

6. THE EXPERIMENTAL ANALYSIS OF BEHAVIOR Applied Behavior Analysis • Contemplative (understanding basic causes of events) vs. technological ideal (using science for control) • Skinner  using science to achieve control • The issue of control • Comparing Watson and Skinner • Attempt to control society • Use of punishment for controlling self-destructive behaviors • Justified? • E.g. Judge Rotenberg Center, Canton, MA

7. SMALL N DESIGNS IN APPLIED BEHAVIOR ANALYSIS A-B Design A-B-A Design Elements of Single-Subject Designs • Importance of operational definitions (again); what constitutes a child’s problematic behavior? • Baselines established • Introduce some treatment • Simplest format: A – B design A = baseline B = treatment A-B-A-B Design Withdrawal Designs • A-B-A • Treatment (B) introduced, then withdrawn • To see if behavior change correlates with treatment change • A-B-A-B • Treatment (B) evaluated twice • Experiment ends with treatment in place

9. SMALL N DESIGNS IN APPLIED BEHAVIOR ANALYSIS A-B-A-B Design • Research Example: Differential Reinforcement of Alternative Behavior (DRA) • Peer-mediated reinforcement of on-task behaviors for ADHD children • External validity issue: laboratory study may not generalize to classroom

10. SMALL N DESIGNS IN APPLIED BEHAVIOR ANALYSIS Multiple-Baseline Designs • Three varieties • One behavior, two or more subjects • Two or more behaviors, one subject • Two or more environments, one behavior, one subject

11. SMALL N DESIGNS IN APPLIED BEHAVIOR ANALYSIS Changing criterion designs • For behaviors that must be changed gradually • Operant principle of shaping

12. SMALL N DESIGNS IN APPLIED BEHAVIOR ANALYSIS Alternating treatments design • Compares relative effectiveness of two or more treatments

13. SMALL N DESIGNS IN APPLIED BEHAVIOR ANALYSIS Evaluating single-subject designs 01 • External validity issues • Visual inspection instead of statistical analysis, although this is changing • Hard to test interaction effects; effect on one type of person but not another?

14. CASE STUDY DESIGNS Survey Research Case study • A detailed analysis of single individual or event • Incorporates other methods (e.g. observation, psychometric tests) • Individual (both clinical and non-clinical cases) • Effects of head trauma in a boxer • The mind of a mnemonist • Autistic savants • Event • Response to catastrophic event

15. CASE STUDY DESIGNS Evaluating case studies Level of detail not found elsewhere Can serve falsification (Remember Hans?) Limited control External validity issues Faulty memory problems Survey Research