Unit 7: Single-Subject Experimental Research Flashcards
ABA design
A within-subject design in which a measurement is taken of the dependant variable (A), then the treatment is introduced and a second measurement is taken (B), then treatment removed and third measurement taken (A).
Demonstrates that the independent variable is responding to the treatment (dependent variable).
ABAB design
Same as ABA but the dependent variable is measured again after a second introduction of the treatment.
single-subject research
Experimental research conducted with one subject, rather than a control and experimental group. the subject serves as their own control by measuring before and after the treatment.
baseline
the behaviour or condition before the introduction of the treatment
treatment
a.k.a. condition - basically the independent variable.
Any way the subject is exposed to a level or levels of the manipulation.
multiple-baseline design
An experimental design that involved introducing multiple treatments at different times under different conditions to determine the effect of the treatment on the dependent variable.
changing-criterion design
An experimental design the introduces increasingly stringent criteria for reinforcement to study the effects of the reinforcement on behaviour.
Compare the assumptions between the single-subject approach and the individual-differences, group-research approach
Single-subject: Changes in an individual’s behaviour are a result of the environmental influences and can be controlled by controlling and manipulating the environment.
Individual-differences group research: differences in behaviour are intrinsic and should be controlled by sampling and stats
What are the advantages of the single-subject approach?
- participants act as their own controls
- avoid ethical issues of not offering beneficial treatment to the control group
- avoids minor variables being distracting
- can adjust the experiment as you go
- greater control for variables means that the effects of specific variables can be studied more closely
- great when there are few possible subjects (ex. rare disease)
What are the disadvantages of the single-subject approach?
- it might be impossible to control for other sources of variability
- some studies are between-subjects by definition
What are the common single-subject research designs?
AB - baseline, post-treatment
ABA - baseline, post-treatment, return to baseline
ABAB - as above but introduce treatment again
Alternating treatments - changing one variable at a time
Multiple baselines - testing the baseline and treatment in multiple times/places
Changing criterion - increasingly stringent criteria for reinforcement tests the effect of the reinforcement
What two principal problems are associated with ABA?
- the effect of the treatment might not be fully reversible or have lasting effects, so the second ‘baseline’ measurement may be misleading
- if the treatment is beneficial, leaving the participants in the untreated state may be harmful or unethical
When is the ABAB design superior to the ABA design?
- when another opportunity to study the treatment effects would be beneficial (ex. to compare results)
- when leaving the P in the treatment state would be beneficial to them
Why is it necessary to maintain a stable baseline before treatment begins?
The baseline is the control condition, so it has to be established for long enough to determine the dependent variable’s characteristics in that condition.
Under what conditions is multiple-baseline design useful?
When it is necessary to consider the influence of environmental or situational factors on the dependent variable. Conducting the treatment for multiple baselines gives indications of the role of situational variables.
