Deck 9: Experimental and Quasi-Experimental Designs

Question 1

A planned quasi-experimental study using a nonequivalent control group design has several extraneous variables that threaten its internal validity. The nurse researcher's actions should be based on which understanding?

A) The results of the study will not be statistically significant.
B) The random assignment of subjects to groups will nullify the intervening variables.
C) The study should be strengthened by controlling intervening variables.
D) Because observation rather than causation is the purpose of the study, no action is necessary.

Answer 1

The study should be strengthened by controlling intervening variables.

Question 2

A study of a program to help people quit cigarette smoking had three groups of subjects. The first group received one supportive phone call 10 days after attending a program on strategies to resist smoking. A second group received a supportive phone call every week for 6 weeks after attending the program. A third group received no supportive phone calls after attending the program. What is the dependent variable in the research scenario?

A) Program on strategies to resist smoking
B) Elimination of cigarette smoking
C) Weekly supportive phone call
D) No supportive phone call

Answer 2

Elimination of cigarette smoking

Question 3

The nurse is critiquing a research study that involves subjects undergoing chemotherapy for breast cancer. Which finding would meet a criterion for inferring causality between performance of exercise and adaptive behavior of the subjects receiving chemotherapy?

A) Adaptive behavior began before the exercise program was initiated.
B) Adaptive behavior occurred in the control group over time.
C) The level of adaptive behavior increased in direct proportion to an increase in the intensity of the exercise.
D) No difference in adaptive behavior was observed between subjects in the experimental group and subjects in the control group.

Answer 3

The level of adaptive behavior increased in direct proportion to an increase in the intensity of the exercise.

Question 4

In which way is the independent variable handled differently in a study with a true experimental design compared with a study with a quasi-experimental design?

A) An experimental design requires an independent variable, whereas a quasi-experimental design neither identifies nor requires an independent variable.
B) Although both designs identify an independent variable, the nature of the groups (randomized versus nonrandomized) means that manipulation may result in different results.
C) Experimental designs demonstrate that the independent variable is related to the outcome, and quasi-experimental studies allow for independent variables that stand alone.
D) Although both designs identify an independent variable, experimental designs identify it before the research is initiated, whereas quasi-experimental designs identify it after the data are analyzed.

Question 5

An after-only nonequivalent control group design would be appropriate to study which of these research questions?

A) What is the effect of the cause of spousal death on widows' self-esteem?
B) What is the effect of preoperative teaching on vascular complications after orthopedic surgery?
C) What is the effect of a mentorship program on improvement of students' clinical performance in a baccalaureate nursing program?
D) What is the effect of a videotaped teaching method on knowledge of adolescent males about the warning signs of testicular cancer?

Question 6

The nurse researcher is planning a study in which subjects will not be randomly assigned to groups. Which type of design would be appropriate for this study?

A) Nonequivalent control group design
B) Posttest only control group design
C) Solomon four-group design
D) True experimental design

Question 7

The experimental treatment initiated by a researcher can be described as what kind of variable?

A) Independent
B) Dependent
C) Extraneous
D) Outcome

Question 8

Which factor should be the primary consideration when determining the validity of experimental study findings?

A) The extent to which the researcher controlled intervening variables
B) The number of subjects who dropped out of the control and experimental groups
C) The credentials and previous experience of the researcher
D) The number of persons involved in the data collection process

Question 9

Randomization strengthens an experimental study in which of these ways?

A) It reduces the risk that a subject will be harmed by participation in the study.
B) It ensures that the experimental group and the control group have the same number of participants.
C) It allows the study to proceed without the researcher knowing which group is the experimental treatment group.
D) It increases the likelihood that the differences in outcomes between the groups are not related to chance alone.

Question 10

Which of these criteria is most important when evaluating the results of an experimental research study?

A) The size of the experimental group compared with the size of the control group.
B) The validity that the experimental treatment caused the desired effect on the outcome.
C) The congruence of research questions to the purpose and hypotheses.
D) The ability of the researcher to apply the findings to clinical or practice settings.

Question 11

A study of a program to help people quit cigarette smoking had three groups of subjects. The first group received one supportive phone call 10 days after attending a program on strategies to resist smoking. A second group received a supportive phone call every week for 6 weeks after attending the program. A third group received no supportive phone calls after attending the program. In the above scenario, which of these properties of experimental research is evident?

A) Quasi-experimental design with no control group
B) Random assignment to research groups
C) Manipulation of the treatment dose
D) Control of extraneous variables

Question 12

In a true experimental study, the control group is the group that does what?

A) Receives the experimental treatment
B) Receives the placebo treatment
C) Experiences the adverse results
D) Experiences the reactive effects

Question 13

A quasi-experimental research design would be preferable to an experimental design in which of these situations?

A) A smaller sample size is sufficient to obtain significant results.
B) Demonstration of a cause-and-effect relationship is the desired outcome.
C) Descriptive statistics will be used to analyze the data.
D) Data will need to be collected in a real-world setting.

Question 14

Compared with a quasi-experimental design, which of these characteristics should a nurse expect to see only in a true experimental design?

A) Experimental treatment
B) Informed consent
C) Hypotheses
D) Random assignment

Question 15

Control is important in an experimental research study for which of these reasons?

A) It ensures maintenance of participant confidentiality.
B) It introduces one or more constants into the experimental situation.
C) It prevents data collection from extending beyond the original time specified for the study.
D) It ensures a cause-and-effect relationship between independent and dependent variables.

Question 16

What type of threat to validity is minimized by the use of a Solomon four-group design?

A) Mortality
B) Selection bias
C) Testing
D) Antecedent variable

Question 17

Which action would increase the control of an experimental study?

A) Establishing strict criteria for subject selection
B) Allowing participants to decide whether or not to be in the experimental group
C) Ensuring that subjects do not know the purpose of the experimental study
D) Increasing the number of assistants involved in data collection

Question 18

Random assignment of subjects to experimental and control groups has which of these effects?

A) Minimizes mortality within groups
B) Maximizes variance between groups
C) Decreases systematic bias
D) Increases selection bias

Question 19

A quasi-experimental study design would be a better choice for a research study than an experimental study design in which of these situations?

A) The study is to be conducted in a laboratory setting.
B) An experimental treatment is not part of the study.
C) The researcher has not conducted research before.
D) Full experimental control is not possible.

Question 20

The nurse is critiquing a research study that used an experimental design. How can the nurse determine if the study's results are able to infer causality?

A) The relationship between independent and dependent variables must be reciprocal.
B) The relationship between independent and dependent variables must not be explainable by any other variable.
C) Both independent and dependent variables should be characterized by reactive effects.
D) Both independent and dependent variables should change as a result of the treatment.

Question 21

How are threats to validity affected when studies are conducted in laboratory settings?

A) Threats to both internal and external validity are increased.
B) Threats to both internal and external validity are decreased.
C) Threats to internal validity are decreased, whereas threats to external validity are increased.
D) Threats to internal validity are increased, whereas threats to external validity are decreased.

Question 22

Which of these research designs could be classified as quasi-experimental? (Select all that apply.)

A) Solomon four-group design
B) After-only design
C) Nonequivalent control group design
D) After-only nonequivalent control-group design
E) One-group pretest-posttest design
F) True experimental pretest-posttest group design
G) Time series design

Question 23

In a study using a true experimental design, which of these methods would control for antecedent variables?

A) Manipulation of the independent variable
B) After-only data collection
C) Intervention fidelity
D) Random assignment to groups

Question 24

How are threats to validity affected when studies are conducted in real-world settings?

A) Threats to both internal and external validity are increased.
B) Threats to both internal and external validity are decreased.
C) Threats to internal validity are decreased, whereas threats to external validity are increased.
D) Threats to internal validity are increased, while threats to external validity are decreased.

Question 25

A study was conducted to determine if videotaped instruction was more effective than written instruction (a pamphlet) to teach menopausal women the benefits of regular mammograms. Which condition would be considered an antecedent variable?

A) There were 38 subjects in the pamphlet group and 34 subjects in the videotape group.
B) During the study, 50% of the videotape group received flu shots, whereas 25% of those in the pamphlet group received flu shots.
C) Four members of the pamphlet group had mothers who had been diagnosed with breast cancer, but no members of the videotape group had mothers who had been diagnosed with breast cancer.
D) While participating in the study, five members of the videotape group began performing breast self-examination (BSE), while two members of the pamphlet group began performing BSE.

Question 26

A research study is planned to determine the effect of nutritional supplementation and type of support surface on the rate of wound healing in sacral myocutaneous flap failures. Which is an independent variable in this study? (Select all that apply.)

A) Rate of wound healing
B) Sacral myocutaneous flap
C) Retailer source of protein supplement
D) Type of support surface
E) Nutritional supplementation

Question 27

Which research designs could be classified as experimental? (Select all that apply.)

A) Solomon four-group design
B) After-only design
C) Nonequivalent control group design
D) After-only nonequivalent control group design
E) One-group pretest-posttest design
F) True experimental pretest-posttest control group design
G) Time series design

Question 28

A nurse researcher is planning a quantitative (experimental) research study to test the effect of a new wound product on wound healing. Which of these factors is necessary to implement an experimental pretest-posttest design? (Select all that apply.)

A) Inclusion of a second control group
B) Ability to collect pretest data
C) Use of two posttreatment data collection times
D) Subjects randomized to the control group only
E) Random assignment of subjects to treatment and control groups

Question 29

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

Question 30

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