Keyton: Communication Research, 5e IM–1
Chapter 6
Populations, Samples, and Sample Size
Activity: Selecting a Sample
The table below contains scores from a communication competence scale. Each score is from a unique
participant. After pairing students into dyads, ask them to select a simple random sample of 20 scores
from the population of scores below using an online random numbers generator ( www.random.org;
http://stattrek.com/statistics/random-number-generator.aspx). After the sample is selected, ask
students to compute the average or mean for their sample of 20. Have each dyad put their average on the
board. What conclusions can you draw about the sampling process by examining the averages?
111
107
100
107
114
115
111
1000
112
104
89
104
102
91
114
114
103
106
105
109
108
113
130
128
128
118
113
120
132
111
124
128
136
106
118
119
123
124
126
116
127
119
97
102
110
120
103
115
93
72
111
103
123
79
119
110
107
74
105
112
105
110
107
103
77
98
90
112
112
114
93
106
The descriptive statistics for the population are:
Mean
108.923077
Standard error
1.49131901
Median
110
Mode
111
Standard deviation
13.1709728
Sample variance
173.474525
Kurtosis
0.64300692
Skewness
–0.5983959
Range
64
Minimum
72
Maximum
136
Sum
8496
Count
78
Keyton: Communication Research, 5e IM–2
Activity: Looking at the Relationships Between Population and Sample Size
Assign or ask students to bring three quantitative studies from communication journals. Ask students to
identify the population, how the sample was selected, and the sample size. Use these examples as the
basis of discussion for these questions:
1. Does the population effectively allow for the communication phenomenon to be studied?
2. How was the sample created?
Worksheet—Sampling
1. Describe how you would select a probability sample from the following identified populations and for
the research purposes:
Population
Research Purpose
How would you select a
sample?
Adults over age 18 with
driver’s licenses in your
state
To determine the degree to which
campaigns about signing organ
donor cards on the backs of driver’s
licenses have been effective
Teenagers (ages 13–18)
who smoke more than five
cigarettes per week
To test the effectiveness of
antismoking messages
Managers and
subordinates who have
worked together for more
than three years
To test the influence of the
manager’s conflict–management
style on subordinates’ perceptions
of manager’s leadership style
2. Network sampling has been used to identify participants for a study of married couples as well as a
study of individuals who have been divorced. Snowball sampling has been used to identify participants
for a study of interracial communication. Describe other sampling methods that would enable you to
conduct research on these three populations
Keyton: Communication Research, 5e IM–3
Additional Resources
Ellis, K. (2001). Teaching the principles of sampling design in the introductory research methods course:
It’s in the beans. Communication Teacher, 12–14.
Kopacz, M. (2010). Studying conflict for Dr. Don: A sampling activity in communication research.
Communication Teacher, 24, 18-23. doi:10.1080/17404620903433382
Professor Kopacz describes an activity that can be completed within a single class period. Students work
in groups to design research questions and find relevant and appropriate samples.
Meltzer, C. E., Gutenberg, J., & Naab, T. (2012). All student samples differ: On participant selection in
communication science. Communication Methods and Measures, 6, 251-262.
doi:10.1080/19312458.2012.732625
Web Resources
For a list of Internet resources, visit https://www.joannkeyton.com/research-methods