» Type I errors occur when researchers reject the null hypothesis when it should have been
accepted. Type II errors occur when researchers accept the null hypothesis when it should
have been rejected.
» Alpha levels of either .05 or .01 are typically used in nursing research. Alpha levels affect the
amount of risk involved for making type I and type II errors.
» Parametric tests are more powerful than nonparametric tests are because they are used with
interval or ratio level data.
» To test for differences between groups, researchers can use Chi square, t test, and ANOVA.
» To test for relationships among variables, Pearson’s r and multiple regression can be used.
» To apply findings to EBP, nurses must be able to interpret statistical tables, differentiate
between clinical and statistical significance, and appraise data analysis.
» To maintain ethical integrity, researchers should select statistical tests and alpha levels in
advance and report incidental findings. It is as important to disseminate nonsignificant
findings as it is to disseminate significant findings.REFERENCES
American College of Physicians—American Society of Internal Medicine. (2001). Primer
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Borenstein, M. (1997). Hypothesis testing and effect size estimation in clinical trials.
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Gillis, A., & Jackson, W. (2002). Research for nurses: Methods and interpretation. Phila-
delphia, PA: F. A. Davis.
Harper, D. (2013). Statistics. Online Etymology Dictionary. Retrieved from http://www
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Hayes, W. L. (1994). Statistics. Boston, MA: Wadsworth.
Hoekstra, R., Johnson, A., & Kiers, H. A. L. (2012). Confidence intervals make a differ-
ence: Effects of showing confidence intervals on inferential reasoning. Educational
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Nieswiadomy, R. M. (2012). Foundations of nursing research (6th ed.). Upper Saddle
River, NJ: Pearson Education.376 CHAPTER 13 What Do the Quantitative Data Mean?