If, after power analysis, a researcher's interventional study ...

[student77]

If, after power analysis, a researcher's interventional study findings are nonsignificant, what might this imply? (Select all that apply.)
 
  a. The effect size was smaller than originally expected.
  b. The effect size was larger than originally expected.
  c. The operational definition of the independent variable was faulty.
  d. The operational definition of the dependent variable was faulty.
  e. A type I error occurred.
  f. A type II error occurred.
  g. The intervention is not an effective one.

Question 2

How are markedly negative results of a multi-site interventional nursing study with a huge sample and stringent level of significance helpful?
 
  a. They rule out the usefulness of the intervention for all clients.
  b. They provide evidence that may change clinical practice, if the intervention is currently being applied in practice to all health care clients.
  c. They contribute to the total body of nursing knowledge.
  d. They may indicate different directions for theoretical ideas.
  e. They establish the fact that the intervention is not universally effective with all clients.
  f. They allow only cautious generalization.

[jgranad15]

Answer to Question 1

ANS: A, C, D, F, G
Negative results could be due to inappropriate methodology, a deviant sample, problems with internal validity, inadequate measurement, poor variable definition, the use of weak statistical techniques, or faulty analysis. Negative results, in any case, do not mean that there are no relationships among the variables or differences between groups; they indicate that the study failed to find any. The sample size was initially judged to have been adequate enough to prevent the risk of a type II error, based on initial calculations, but if the effect size was very small, a type II error might have occurred. The negative results could be a true reflection of reality. In this case, the reasoning of the researcher or the theory used by the researcher to develop the hypothesis is in error.

Answer to Question 2

ANS: B, C, D, E
The negative results could be a true reflection of reality. In this case, the reasoning of the researcher or the theory used by the researcher to develop the hypothesis is in error. Since this was a huge multi-site interventional study, it establishes the fact that the intervention does not work with a sizable number of clients. This is useful to know.