Chapter 11 – Experimental Designs

1. The manipulation of the independent variable is also known as the treatment, and the results of the treatment are called treatment effects.

a. T

b. F

2. External validity of lab experiments refers to the confidence we place in the cause-and-effect relationship.

a. T

b. F

3. Internal validity refers to the extent of generalizability of the results of a causal study to other settings.

a. T

b. F

4. Cause-and-effect inferences can be contaminated by the effects of the passage of time. Such contamination effects are denoted history effects.

a. T

b. F

5. A time series design thus allows the researcher to assess the impact of a treatment over time.

a. T

b. F

6. A Quasi-Experimental Design measures true cause-and-effect relationships.

a. T

b. F

7. A Quasi-Experimental Design guarantees the maximum internal and external validity, ruling out many other rival hypotheses.

a. T

b. F

8. Major threats to validity in a “pretest & posttest with one experimental group only” are:

a. History, maturation, main testing, interactive testing, mortality.

b. Statistical regression, maturation, main testing, interactive testing, mortality.

c. Statistical regression, instrumentation, main testing, interactive testing, mortality.

d. History, instrumentation, main testing, interactive testing, mortality.

9. Experimental designs fall into two categories: experiments done in an artificial or contrived environment, known as lab experiments, and those done in the natural environment in which activities regularly take place, known as field experiments.

a. T

b. F

10. Compared to randomization, matching might be less effective, since we may not know all the factors that could possibly contaminate the cause-and-effect relationship in any given situation, and hence fail to match some critical factors across all groups while conducting an experiment.

a. T

b. F

11. Internal validity of experiments refers to the confidence we place in the cause-and-effect relationship.

a. T

b. F

12. Field experiments have more external validity, but less internal validity. In the lab experiment, the reverse is true.

a. T

b. F

13. An interactive testing effect occurs when the prior observation (the pretest) affects the later observation (the posttest).

a. T

b. F

14. Interactive testing effects typically occur because participants want to be consistent.

a. T

b. F

15. Quasi-Experimental Designs expose an experimental group to a treatment and measure its effects.

a. T

b. F

16. A Quasi-Experimental Design does not measure true cause-and-effect relationships.

a. T

b. F

17. History effects (the dropout of individuals from groups) is a problem for all experimental designs.

a. T

b. F

18. A pretest and posttest experimental group design guarantees the maximum internal and external validity, ruling out many other rival hypotheses.

a. T

b. F

19. A key problem of time series is history: certain events or factors that have an impact on the independent variable–dependent variable relationship might unexpectedly occur while the experiment is in progress.

a. T

b. F

20. Major threats to validity in a “pretest & posttest with one experimental group only” are:

a. History, maturation, main testing, interactive testing, mortality.

b. Statistical regression, maturation, main testing, interactive testing, mortality.

c. Statistical regression, instrumentation, main testing, interactive testing, mortality.

d. History, instrumentation, main testing, interactive testing, mortality.

21. A simulation can be thought of as an experiment conducted in a specially created setting that very closely represents the natural environment in which activities are usually carried out.

a. T

b. F

22. Biases that might affect the internal validity of experimental designs are often increased by enhancing the level of sophistication of the experimental design.

a. T

b. F

23. The Solomon four-group design, also known as the four-group six-study design, controls for all the threats to internal validity.

a. T

b. F