SSRD Workshop 1
Single Subject Research Design (SSRD)
Bill Miller, PhD, OT UBC School of Rehab Sciences
VCHA OT Research Scientist
SSRD Workshop 2
Objectives
⢠Define Single Subject Research Design (SSRD) ⢠Rationale for using SSRD ⢠Describe several forms of SSRD ⢠Discuss the methods of analyses using SSRD ⢠Discuss strengths & weaknesses of SSRD
SSRD Workshop 3
Continuum of Research
Quasi-Experimental (Groups -no random selection)
Case report Case Study (Individuals - SSRD)
Experimental (RCT)
Pre Scientific Scientific
SSRD Workshop 4
Other Names for SSRD
⢠Single case experimental design ⢠Time series design ⢠Small-N design ⢠Single system designs ⢠Within-subject comparison ⢠Idiographic research ⢠N of one trial
SSRD Workshop 5
SSRD Defined
SSRD involves studying a single individual or system by taking repeated measurements of 1
or more dependent variables and systematically applying & sometimes, withdrawing or varying the independent
variable. (Ottenbacher, 1986; Bloom & Fischer, 1982)
SSRD Workshop 6
Why Chose SSRD?
⢠Demonstrates individual differences ⢠Difficulty obtaining adequate power (N) ⢠Difficulty obtaining homogeneous group ⢠SSRD is relatively easy to do ⢠Helps validate practice ⢠Demonstrate treatment (tx) effectiveness ⢠Great pilot
SSRD Workshop 7
About SSRD
⢠Collection of methods (eg; AB, ABAC) ⢠Answers research question or tests hypothesis ⢠Involves at least one;
⢠Subject (individual or clinical unit/department) ⢠Baseline or "A" Phase - series of repeated observations
or measurements with no intervention ⢠Intervention or "B" Phase - introduction of experimental
variable with evaluation to see if change occurs ⢠Dependent variable (quantifiable) ⢠Independent variable (treatment / intervention)
SSRD Workshop 8
SSRD Phases
Baseline ⢠Period of no tx - reflects natural state ⢠Provide standard for evaluating tx effect ⢠Measurements usually repeated until stability
demonstrated ⢠5 or...