Lecture 1 Flashcards
What is the main reason to use experimental study designs?
The ability to conclude there is a causal correlation between two variables.
List the three basic conditions for concluding causality.
- Two variables vary together.
- There is a time order.
- There is an ability to rule out alternative explanations.
What are the four advantages of control in research?
- Directionality.
- Exclusiveness.
- Sensitivity and magnitude.
- Reproducibility.
According to Cook & Campbell (1979), what are the four criterions for validity of experimental findings?
- Statistical conclusion validity.
- Internal validity.
- Construct validity.
- External validity.
True or False: The validity of experiment findings is the same as the validity of the measure.
False
What does statistical conclusion validity assess?
Whether there is a statistically significant correlation between the independent variable (IV) and the dependent variable (DV).
What decision is made at the end of the hypothesis testing procedure?
To reject or not to reject the null hypothesis.
What is Type I Error (α)?
The probability of incorrectly rejecting the null hypothesis when it is true.
What is internal validity concerned with?
The ability to find a causal correlation, and whether the experimental treatment causes differences in the DV.
Define ‘artifact’ in the context of internal validity.
An external variable that might act as an alternative explanation for the IV-DV correlation.
List three potential sources of threats to internal validity.
- The way the research is conducted.
- The participants.
- The experimenters.
What is a true experiment?
An experiment that enables ruling out alternative explanations to the effect, involving random assignment to conditions.
What are quasi-experimental designs?
Research designs that are not true experiments and suffer from threats to internal validity.
Give an example of a quasi-experimental design.
One-group posttest-only design.
What does construct validity assess?
Whether the causal correlation found exists between the theoretical variables that the operational variables represent.
What are the two reasons for a lack of congruency between operational and theoretical definitions?
- The operational definition isn’t exhaustive.
- The operational definition isn’t exclusive.
What does external validity refer to?
The ability to generalize the results beyond populations, times, and situations.
List three factors that relate to external validity.
- Sampling.
- Ecological validity.
- Replication.
What is the solution to interaction of testing X treatment?
A control group with no pretest measure, only a posttest measure.
What is the purpose of random sampling?
To ensure the sample characteristics represent the population characteristics.
Define ecological validity.
Whether the procedure used mirrors real life.
What is replication in research?
Conducting a study that repeats or duplicates in some systematic manner a previous study.
What are the three types of replication?
- Exact (direct/literal) replication.
- Partial replication.
- Conceptual replication.
What is the main focus of Buss’s study on long-term mate preferences?
To examine sex differences in human mate preferences across cultures.
Which type of validity is considered most important?
Internal validity.
