Generating and assessing evidence for nursing practice

Data Analysis


Polit, D. F., & Beck, C. T. (2012). Nursing research: Generating and assessing evidence for nursing practice (9th ed.). Philadelphia, PA: Lippincott Williams & Wilkins.
This chapter introduces descriptive statistics, which, as the name implies, describe characteristics of the data. There is an overview of the different levels of measurement—nominal, ordinal, interval, and ratio—and how they are used. The chapter also defines frequency distributions and distinguishes between univariate and bivariate descriptive statistics.
Chapter 17, “Inferential Statistics”

This chapter focuses on inferential statistics, which are based on the laws of probability. It introduces sampling distributions, estimates of parameters, and levels of significance. In addition, the chapter provides an overview of some of the most commonly used inferential statistical tests, including t-tests, analysis of variance (ANOVA), and chi-square tests. Finally, the process of testing correlations is examined.
Chapter 18, “Multivariate Statistics”

In this chapter, the focus shifts to multivariate statistics. These are often used when the data analysis involves three or more variables. The multivariate tests described include simple linear regression, multiple linear regression, analysis of covariance (ANCOVA), causal modeling, and event history analysis.
Chapter 19, “Processes of Quantitative Data Analysis and Interpretation”

The previous chapters have described a number of different statistical tests used to examine data in a quantitative study; this chapter focuses on how to analyze and interpret the results. It describes the steps in the analysis process and how to determine the credibility of the results.
Chapter 23, “Qualitative Data Analysis”

The focus of this chapter is qualitative data analysis, which is more difficult in some ways than quantitative analysis, because there are not specific tests that can be used. Instead, much of the analysis is based on the researcher’s ability to identify patterns of behavior or similarities in events. Suggestions are provided for analysis of each of the major types of qualitative studies and how to document findings.


As a nurse engaged in evidence-based practice, it is important to recognize how statistics and other data analysis tools are used to generate and assess evidence. Most nurses need only a foundational understanding of statistical tools and terminology to understand the majority of research studies. As a nurse, you should be able to recognize the most commonly used statistical tests, how and when they are used, and how significance is determined.

In this Discussion,examine different types of statistics and statistical tests, when and why these particular tests would be selected for use, and, most importantly, what the results indicate. To this end, you will be assigned to a group by Day 1 of this week. Each group will be assigned one of the five chapters listed in this week’s Learning Resources and will develop a study sheet on their chapter that will be shared with the other groups.
To prepare:

Review the information in assigned chapter.

Develop a 1-page study sheet that includes the following:

The key concepts of the chapter: Focus on the basic concepts that are important for nurses to understand as they review research studies.
A description of the statistical methods covered in the chapter, what they measure, and under what circumstances they are used. Identify examples of how the statistical methods have been used in research studies.
An explanation of the key statistical tests and how they measure significance .

Discuss why it is important for nurses to understand the basics of these statistical methods.