Evidence-Based Practice for Nurses

shows how raw data are tallied and the resulting frequencies and percentages

are recorded. The left-hand side of the table shows the frequency with which

individual age data occur. Because all possible data points are presented, it is

still somewhat difficult to comprehend this presentation of the ungrouped data.

The right-hand side of the table shows a grouped frequency and percentage dis-

tribution with the ages grouped in 2-year increments. It should be obvious that

the grouped data are more meaningful than either the raw or ungrouped data.

Although there are few fixed rules regarding how and when to group data,

it is imperative that there be no overlap of categories. Each group must have

well-defined lower and upper limits so that the groups are mutually exclusive,

yet the groups must include all data collected. For example, if the groupings

in Table 13-3 had been 18–20 and 20–22, people who are 20 years old would

have been counted in both groups, and the statistics would have been com-

promised. Group size also should be consistent. If the groups had been 18–20

(a 3-year span), 21–25 (a 4-year span), and older than 25 (a 3-year span), then

inaccurate analysis of data would occur. Although grouping data might make

Variable n(%)

Gender

Men

Women

14 (41)

20 (59)

Race/Ethnicity

White/Caucasian

Black/African American

Hispanic/Latino

Native American/Eskimo

Asian/Pacific Islander

No answer

190 (76.0)

32 (12.8)

12 (4.8)

3 (1.2)

2 (0.8)

11 (4.4)

Self-Care Behaviors

Current smoker

Alcohol > 1 drink/day

Exercise

No regular exercise

1–2 days/week

3–4 days/week

≥ 5 days/week

7 (18)

0 (0)

9 (27)

10 (29)

8 (24)

5 (15)

n = number in group; % = percent

TABLE 13-2

Example of Categorical Data

Presented in Ungrouped Format

334 CHAPTER 13 What Do the Quantitative Data Mean?