Chapter 9 Pwpt

Question 1

Experimental and Quasi experimental designs both?

Answer 1

The researcher manipulates the study variables in order to achieve a desired effect
Test cause and effect relationships
Provide Cochrane level 2 and level 3 evidence

Question 2

Cochrane levels of evidence:

Answer 2

Level 1: systematic reviews
Level 2: RCTs (randomized controlled trials)
Level 3: quasi experimental studies

Question 3

A true experimental design is known as? And has three properties:

Answer 3

Is known as a Randomized control trial (RCT)

Randomization
Control
Manipulation

Question 4

Cause and effect relationships need:

Answer 4

The causal (independent) and effect (dependent) variables must be associated with each other

The cause must precede the effect

The relationship must not be explainable by another variable

Question 5

How is control acquired?

Answer 5

Manipulating the independent variable so that X happens before Y

Random assignment

Using a control group

Question 6

Randomized clinical trials

Answer 6

Intervention fidelity ensures that every subject receiving the intervention receives the identical intervention

Use statistical comparisons to determine differences

Have a specific sampling plan, using inclusion and exclusion criteria

Sample size is important, (too large=wastes time, money, resources,) (too small= may lead to inaccurate results)

Question 7

A RCT is most powerful for..?

Answer 7

Testing cause and effect relationships because of the use of control, manipulation and randomization

Question 8

A classic randomized clinical trial:

Answer 8

Sample is selected from population —> baseline data are collected —> subjects are randomized —> control group/intervention group —> post intervention data are collected

Question 9

Weakness of the experimental design

Answer 9

Complicated to design
Costly to implement
Difficult to implement

Question 10

Quasi experimental design

Answer 10

Also tests cause and effect relationships by manipulating the independent variable
Randomization may not be possible, or there may not be a control group (less convincing)
Provides Cochrane level 3 evidence

Question 11

Nonequivalent control group design

Answer 11

Experimental group —> baseline data are collected —> intervention is applied —> postintervention data are collected

Control group—> baseline data are collected—> data are collected again

Question 12

Nonequivalent control group design means?

Answer 12

Experimental and control group but no randomization

Threats to internal validity include: selection, maturation, testing, mortality

Results of the study are still strong because researcher is still able to compare the two groups before intervention

Question 13

One group only (pre test-posttest) design means?

Answer 13

Used when only one group is available for study

Only an experimental group; data are collected before and after an experimental treatment

No control group, no randomization

Question 14

One group design (protest-posttest design)

Answer 14

Experimental group —> baseline data are collected —> intervention is applied—> postintervention data are collected

Question 15

Strengths of a quasi experimental design

Answer 15

Practical, less expensive, generalizable, sometimes only feasible alternative

Replication of the study overtime can strengthen evidence

Question 16

Weaknesses of a quasi experimental design

Answer 16

Unable to demonstrate clear cause and effect relationships

Question 17

Criteria for critiquing experimental and quasi experimental designs

Answer 17

Is the design used appropriate to the study question?
Is the design pragmatic for the setting or sample?
Is there a detailed description of the intervention?
Are there any reasons to believe that there are alternative explanations for the findings?
Are the findings generalizable to the larger population of interest?

Question 18

What is the best response in the following scenario?

A nurse researcher has determined that an intervening variable might slightly affect both randomized sample groups.

Answer 18

Continue as before

Question 19

Which type of research design is described?
A wellness center wishes to determine whether a stress reduction series of classes increases perceived efficacy of participants. A pre/post questionnaire was administered to all participants.

Answer 19

Quasi-experimental

Question 20

What question is most important when evaluating the evidence from an experimental study?

Answer 20

Could something else explain the results?

Question 21

Which type of research design is most likely used in the following scenario?

A nurse researcher is investigating the effects of yoga on blood pressure. One group of subjects is participating in a yoga class and the other group is not.

Answer 21

Experimental