Experiments that revolve around the behaviour of an individual case in an attempt to modify the behaviour of that case
Single-case experimental designs
Key features of single case experiments
- Participants are their own control
- Interchanging treatment and baseline phase
- Multiple measurements per replication/phase
- data is examined separately per case
- A visual analysis is used
Advantages of single case experiments
- Requires a small amount of participants to work
- Can be used to study rare cases
- Used to examine if an intervention works on a specific case
- Flexible
- You can’t average results, so extreme results are not ignored
A subfield of psychology that examines the relation between physical properties of stimuli and sensory-perceptual responses
psychophysics
An approach to a study that under controlled conditions environmental stimuli and consequences regulate an individual’s behaviour
experimental analysis of behaviour
A field of clinical research that applies the experimental analysis of behaviour to problems of social importance
applied behavior analysis
A sequence of phases where the treatment is either absent or present
ABAB designs or withdrawal designs
What does A, B and C represent in single-case designs
A is the lack of treatment
B is the treatment
C would then be treatment condition 2
The desired behaviour change
target behavior
Why do single-case designs have a withdrawl phase
This is to ensure that it is actually the treatment that caused the change in behaviour
Limitations of ABAB designs
- You cannot ethically remove the treatment if it proves to give a positive change in behaviour
- it is difficult to draw conclusions if the withdrawal phase does not cause a return to the baseline
A single-case design that is like an ABAB in the first participant, then there is a modification in the second experiment
Multiple-baseline designs
Two or more participants are exposed to the same treatment, but at different times
multiple-baseline design across subjects
The same treatment is applied to two or more times to the same individual, but different behavior changes are measured
a multiple-baseline design across behaviours
The same treatment is applied to the same target behaviour in multiple settings
multiple-baseline design across settings
Limitations of multiple-baseline designs
- Cannot draw causal conclusions
- Is it ethical to withhold effective treatements
A baseline phase is followed by a treatment phase that lasts until the target behaviour meets a criteria, then a new phase with a different criteria starts.
changing-criterion design
Does a single-case design need to only be one person?
No, the single case could be a social unit
Limitations of single-case studies
- Vulnerable to order effects
- Difficult to rule out alternative explanations
- Not effective in their ability to examine all potential interactions
- No external valididty
