Singel Subject Design Flashcards
Hierarchy of Scientific Evidence:
1 (toppen av pyramiden) - Meta-Analysis and Systematic Review
2 - Randomized controlled trials.
3 - Cohort Studies.
4 - Case-Control studies.
5 - Cross Sectional studies.
6 - Animal trials and in vitro studies.
7 - Case report, opinion papers, and letters.
Single-case research design:
The phenomena of interest are studied using a single subject or a small group of research subjects (also referred to as N-of-1 designs or single-subject research).
The 3 Major types of single-case research:
1) Case studies
2) Quasi experimental designs
3) Experimental designs
1) Case studies:
- Refers to a broad array of approaches, most often used for observing an individual and reporting on their interactions with variables of interest.
- Unit case studies : Individual, Family, Class
Advantages of case studies:
- do not require control conditions or comparison group.
- can be easily incorporated into routine clinical work.
- offer clinicians both a useful research tool as well as a source of data directly relevant to clinical practice.
- valuable in the study of rare phenomena.
- provide opportunity to observe the behavior of interest “as it naturally occurs”, which may be useful for generating a hypothesis.
- provide an incredibly efficient and flexible tool in the assessment and treatment development and evaluation process.
Disadvantages of case studies:
- Lack the methodological requirements to draw valid inferences about relations among variables.
- Typically do not include design features such as objective assessment, systematic data collection or analysis, specified manipulation of the independent variable, or replication of treatment effects.
Clinical Research:
How do I help the most people with these kinds of problem?
Clinical Practice:
How do I help this person sitting in front of me right now?
Single case studies:
- Avoids small, unimportant effects
- Links science to practice, and practice to science.
- Facilitates innovation.
- Fits into clinical settings.
- Creative and flexible.
Single case design essentials:
- Internal validity - effect because or intervention? -> adequate comparison conditions.
- External validity - Generalize? -> replicate, replicate, replicate.
This requires - repeated continues measurements and systematic manipulation of intervention.
2) Single-case Quasi-experimental design:
- Repeated assessment of the dependent variable -> reliable and valid measures, should occur early, frequently, and consistently , should be feasible.
- Intervention -> independent variable, can be behavioral, cognitive, psychodynamic, or other methods, intervention should be well specified.
- Choose intervention targets that are: Frequent, concrete and quantifiable, stable without treatment.
3) Singe-case Experimental design:
- Includes a controlled variation of the independent variable and measurement of the effects of this variation allowing the experimenter to examine causal relations between intervention and outcome.
- Design essentials -> Multiple phases and conditions, Replication of experimental effects.
Multiple phases and conditions:
- Each individual participates in both treatment and control conditions.
- The vital element is the inclusion of multiple conditions (that it, >1) for each subject.
- A=non-treatment phase
- B=treatment phase
- Examples: ABA or ABAB.
Replication of experimental effects:
- Replication of experimental effects should occur both within and between studies.
- This is one of the greatest strengths of such approaches.
Primary Research Design:
- Reversal design
- Multiple-Baseline Designs
- Changing Criterion Designs