A research study in a laboratory setting incorporates four groups ...

[Yolanda]

A research study in a laboratory setting incorporates four groups (two control and two experimental) in which only one experimental group and one control group are pretested, while all four groups are posttested.
 
  Which descriptions of the design are accurate? (Select all that apply.)
  a. Experimental design
  b. After-only experimental design
  c. Real-world experimental design
  d. Quasi-experimental design
  e. Solomon four-group design

Question 2

Which are characteristics of quasi-experimental research designs that are considered weaknesses, compared with experimental designs? (Select all that apply.)
 
  a. Cost of implementation
  b. Confidence in making causal assertions
  c. Subject to contamination of internal validity
  d. Disruptive to the usual routine of the setting
  e. Difficult to perform in a particular clinical setting
  f. Findings due to interference of extraneous variables

[Juro]

Answer to Question 1

ANS: A, E

Feedback
Correct The example describes a type of experimental design, a Solomon four-group design.
The example describes a Solomon four-group design.
Incorrect An after-only experimental design does not include any pretesting.
A real-world experimental design would be conducted in an actual practice setting, not a laboratory.
The example describes an experimental study conducted in a laboratory. A quasi-experimental design would be conducted in a real-world setting.

Answer to Question 2

ANS: B, C, F

Feedback
Correct The primary weakness of quasi-experimental designs, compared with experimental designs, is the weakened confidence in making causal assertions.
Quasi-experimental designs are particularly subject to contamination of internal validity by extraneous variables.
Findings of quasi-experimental studies may be due to the influence of extraneous variables, rather than the experimental treatment (independent variable).
Incorrect The costs associated with quasi-experimental designs are generally much lower than the costs of experimental designs.
Quasi-experimental designs are much less disruptive to the usual routine of the setting than experimental designs.
Quasi-experimental designs are easier to perform in a particular clinical setting than experimental designs.