PSYC*2360 Chapter 12: Mixed Design Flashcards
What is a single-subject design?
A type of within-subjects design using one participant or one group to assess changes within that individual or group
What is a single-subject design also known as?
- A single-case experimental design
- A single-n design
What are three types of single-subject designs?
- The A-B design
- The A-B-A design
- The A-B-A-B design
What are the two phases of an A-B design?
-Phase A: Take baseline measurement
- Phase B: Introduce intervention or experimental treatment and take measurement again
T or F: The change in measurement from the A phase to the B phase might suggest a causal relation.
True
In an A-B design, what might the second measure (B) be more easily influenced by?
Extraneous factors
What are the three phases of an A-B-A design?
- Phase A: Take baseline measurement
- Phase B: Introduce intervention or experimental treatment and take measurement again
- Phase A: Remove the intervention and take the measurement again
How does an A-B-A design help establish covariation?
By showing that behaviour systematically changes as researchers introduce and remove treatment
What are the four phases of an A-B-A-B design?
- Phase A: Take baseline measurement
- Phase B: Introduce intervention or experimental treatment and take measurement again
- Phase A: Remove the intervention and take the measurement again
- Phase B: Reintroduce intervention and take measurement again
Which type of single-subject design provides the best evidence of causality?
The A-B-A-B design
What are two weaknesses of single-subject designs?
- No control group
- Low external validity/ability to generalize findings
T or F: Some argue that the participant/group serves as the control group whenever the treatment is removed in an A-B-A or A-B-A-B design.
True
What is a mixed design?
An experimental design that combines within-subjects and between-subjects methods of data collection
T or F: In a mixed design, all participants receive every level of the between-subjects factor, but only one level of the within-subjects factor.
False. All participants receive every level of the WITHIN-subjects factor, but only one level of the BETWEEN-subjects factor.
What are two benefits of mixed designs?
- The strengths of a within-subjects design help compensate for the weaknesses of the between-subjects design and vice versa
- Allows the research to answer more than two questions (main effects of each IV and interaction effects between IVs)
What is the main strength of a between-subjects design?
High internal and external validity
What is the main weakness of a between-subjects design?
Low power
What is the main strength of a within-subjects design?
High power
What is the main weakness of a within-subjects design?
Low internal and external validity
What are two types of control groups commonly used in clinical research?
- Treatment-as-usual group
- Waiting-list group
What is a treatment-as-usual control group?
A group in which an already established treatment is administered for comparison to the experimental treatment
What is a waiting-list control group?
A control group in which participants don’t receive any treatment of intervention until after the completion of the study
Are baseline measures taken from the waiting-list control group?
Yes
T or F: Once the study’s results are clear and the best form of intervention is identified, participants in the waiting-list control have the first opportunity to receive the best treatment, but must still pay.
False. They receive the treatment at no cost.
What is the experimenter-expectancy effect?
When a bias causes a researcher to unconsciously influence the participants
What is the experimenter-expectancy effect also known as?
- Expectancy bias
- Experimenter bias
What is one way to reduce the experimenter-expectancy effect?
Use a double-blind procedure
What is a double-blind procedure?
A protocol in which neither the participants nor the administrators of treatment are aware of which treatment is being provided
What is a single-blind procedure?
A protocol in which the participants are unaware of which treatment they are receiving, but the administrator knows
How can bias be minimized in a single-blind procedure?
By not sharing the hypothesis
Which statistical analysis tests for differences between two or more categorical independent variables, where at least one is a between-subjects variable and another is a between-subjects variable?
A mixed design ANOVA
A mixed design ANOVA can be described as a combination of what two statistical tests?
A repeated-measures ANOVA and a factorial ANOVA
When presenting the findings from a mixed design ANOVA, what are the two values in the parentheses that follow F (F(X, Y)=)?
- X= Between-subjects degrees of freedom
- Y= Within-subjects defrees of freedom