10.5: Single-Subject Research (Summary)
- Page ID
- 309676
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)Key Takeaways
Key Terms and Concepts
SINGLE-SUBJECT RESEARCH
Intensive study of individual participants with repeated measurements over time.
GROUP RESEARCH
Research studying many participants to draw general conclusions.
SOCIAL VALIDITY
The importance and acceptability of research goals, procedures, and outcomes.
EXPERIMENTAL ANALYSIS OF BEHAVIOR
Basic research on principles of behavior using single-subject designs.
APPLIED BEHAVIOR ANALYSIS
Applying behavioral principles to solve real-world problems.
STEADY STATE STRATEGY
Establishing a stable baseline before introducing treatment.
REVERSAL DESIGN
Introducing and withdrawing treatment to demonstrate experimental control.
ABA DESIGN
Baseline phase, treatment phase, then return to baseline.
BASELINE
Initial observation period without treatment to establish typical behavior.
MULTIPLE-TREATMENT REVERSAL DESIGN
A baseline phase followed by several phases with different treatments.
ALTERNATING TREATMENTS DESIGN
Rapidly alternating between two or more treatments.
MULTIPLE-BASELINE DESIGN
Staggered introduction of treatment across behaviors, participants, or settings.
VISUAL INSPECTION
Examining graphs to determine whether treatment produced an effect.
TREND
A systematic increase or decrease in the dependent variable over time.
LATENCY
The time between treatment introduction and behavior changes.
PERCENTAGE OF NON-OVERLAPPING DATA
Percentage of responses in the treatment condition that are more extreme than the most extreme response in a relevant control condition.
EXTERNAL VALIDITY
The generalizability of findings to other people, settings, or times.
CONVERGING EVIDENCE
Multiple studies using different methods reaching the same conclusion.
Test Your Knowledge (answers at end of section)
1. What is single-subject research?
A. Research that always involves exactly one participant
B. Quantitative research studying in detail the behavior of each of a small number of participants
C. Qualitative case study research focusing on subjective experience
D. Research conducted in isolation from group studies
2. Why is it important to focus intensively on individual participants in single-subject research?
A. It is less expensive than group research
B. Group research can hide individual differences and the behavior of a particular individual may be of primary interest
C. Individual participants are always more reliable than groups
D. It eliminates the need for statistical analysis
3. What is the steady state strategy in single-subject research?
A. Keeping all conditions exactly the same throughout the study
B. Changing conditions after a fixed time regardless of behavior
C. Waiting until behavior becomes fairly consistent before changing conditions
D. Never changing experimental conditions
4. The most basic single-subject research design is the:
A. Multiple-baseline design
B. Reversal or ABA design
C. Alternating treatments design
D. Factorial design
5. Single-subject research is particularly good for:
A. Testing weak, inconsistent effects
B. Studying variables that cannot be manipulated
C. Testing effectiveness of treatments on individuals with strong, consistent, biologically or socially important effects
D. Large-scale population surveys
6. The principle of converging evidence suggests that:
A. One perfect study can prove a theory
B. Scientists should examine patterns across multiple studies with different strengths and weaknesses
C. Only experimental research is valid
D. Media conclusions from single studies are always reliable
Answer Key with Explanations
1. B - Quantitative research studying in detail the behavior of each of a small number of participants
Single-subject research is quantitative research that involves studying in detail the behavior of each of a small number of participants (typically 2-10). The term 'single-subject' refers to the intensive focus on each individual, not that only one participant is studied.
2. B - Group research can hide individual differences and the behavior of a particular individual may be of primary interest
Group research can hide individual differences—a treatment with positive effects for half the people and negative effects for the other half would appear to have no effect on average. Also, sometimes the behavior of a particular individual (e.g., a specific disruptive student) is of primary interest.
3. C - Waiting until behavior becomes fairly consistent before changing conditions
The steady state strategy means the researcher waits until the participant's behavior becomes fairly consistent from observation to observation before changing conditions. This makes it easier to detect any change when conditions do change.
4. B - Reversal or ABA design
The reversal design (also called ABA design) is the most basic single-subject design. It consists of a baseline phase (A), treatment phase (B), and return to baseline (A), and can be extended to ABAB or longer sequences.
5. C - Testing effectiveness of treatments on individuals with strong, consistent, biologically or socially important effects
Single-subject research is particularly good for testing treatment effectiveness on individuals when the focus is on strong, consistent, and biologically or socially important effects. It's also useful when the behavior of particular individuals is of interest.
6. B - Scientists should examine patterns across multiple studies with different strengths and weaknesses
Converging evidence means evaluating theories by looking at overall trends across multiple studies. If studies with different designs and different flaws all converge on the same conclusion, confidence increases dramatically.