Single Subject Research Design in a School System

1
Single Subject Research Design in a School System

• Sandra Rogers, Ph.D., OTR
• School of Occupational Therapy
• Pacific University

2
Objectives

• Review single-subject research design (SSRD)
• Highlight clinical utility of SSRD and provide
  examples of use in pediatrics
• Problem solving to identify clients, treatment
  strategies to allow recording
• Identify possible methods to implement as a
  school-wide data collection system

3
Single Subject Research Design

• Systematic data collection in the natural
  setting.
• Independent variable (treatment) is identified
  and operationally defined
• Dependent measure (outcome) is identified and
  operationally defined
• Demographic information collected

• Design selection determines how variables will be
  manipulated
• Data must be accurately reliably collected
• Data must be appropriately analyzed
• Make comparisons between treatment and no
  treatment

4
Characteristics of Single Subject Research Design

• Involve only 1 person or a small group that is
  treated as a unit
• Comparisons are made within subjects not between
  subjects
• Responses to intervention are recorded repeatedly
  over a period of time
• Responses to intervention are collected at
  regular intervals
• Subject feedback is carefully monitored.
• Process is studied as well as outcome.

5
Characteristics Continued

• Modifications in design and measurement are
  possible during the study, are individual and
  flexible.
• Findings are directly relevant to a specified
  patient, can not generalize to other subjects.
• Emphasis is on knowledge for immediate, practical
  use.
• Costs are small and procedures are usually
  incorporated as part of a clinical routine.
• Limitations are present

6
SSR Design

• Independent variable is the intervention
• Dependent variable is the target variable
• Dependent variable must be observable,
  quantifiable, and a valid indicator or treatment
  effectiveness

7
SSR Design Used to

• Study comparisons between several treatments
• Between components of treatments
• Between treatment and no treatment
• Sequential activities-training strategies or
  techniques to shape behaviors
• Lots of design flexibility

8
Repeated measures

• Systematic collection of repeated measures of a
  behavior over time
• Regular intervals
• Once a day
• Twice during treatment session
• Once a week
• Required to observe the trend in data and
  evaluate the variability

9
Design Phases

• Two phases
• Baseline phase
• Intervention phase
• Target behavior (dependent variable) is
  repeatedly measured across both phases
• Plotted on a graph

10
Baseline Phase

• Stability
• Consistency over time
• Most desired to have a consistent level of
  behavior with minimal variablity
• Trend
• Changes over baseline indicate the trend of the
  intervention

11
SSR Designs

• AB
• ABA
• ABAB
• BAB
• Multiple baseline

12
Implementation process

• Identify a clinical interest/irritation
• Identify a strategy (independent variable).
• Identify an expected outcome measure (dependent
  variable)
• Select a design
• Select method to analyze
• Write up results, interpret share