Evidence-Based Practice for Nurses

trials (RCTs) are considered to be the strongest level of

evidence, whereas those based on case reports and opin-

ions of experts and authorities are considered to be the

lowest level of evidence (Myers & Meccariello, 2006). In

quantitative studies, research questions and hypotheses

are derived from theories. The study design reflects the

objectives of the study. Researchers must decide how each

variable will be operationalized and what types of data will

need to be gathered. The main methods used in quantitative research include

questionnaires, observation, scales, and physiological measures. Table 10-1

provides an overview of data collection methods that are associated with vari-

ous quantitative research designs.

Questionnaires

Questionnaires are commonly used in quantitative research and can provide

an inexpensive way to gather numerical data from a potentially large number

of respondents. Although questionnaires may be inexpensive to administer,

when compared to other data collection methods, they can be expensive in

terms of design time and interpretation. It is essential that each question is

monitored for clarity, sensitivity to the respondent, reading level, and absence

of bias (Sinkowitz-Cochran, 2013).

Quantitative Research Design Data Collection Methods

Exploratory/descriptive

(answers what questions; describes

frequency of occurrence)

Questionnaire

Scales

Correlational

(examines relationships among

variables)

Questionnaire

Scales

Biophysiological

Quasi-experimental

(examines why certain effects occur)

Questionnaire

Scales

Biophysiological

Experimental/clinical trial

(examines causes of certain effects)

Questionnaire

Scales

Biophysiological

TABLE 10-1

Quantitative Research Designs

and Data Collection Methods

FYI

Regardless of how the data are collected,

researchers must consider a variety of issues

to ensure a high-quality study. Interrater

reliability must also be established when

more than one person is involved in making

observations.

KEY TERM

questionnaires:

Printed instruments

used to gather

numerical data

256 CHAPTER 10 Collecting Evidence