Instructor Resource
Treadwell and Davis, Introducing Communication Research: Paths of Inquiry, 4e
SAGE Publishing, 2020
Lecture Notes
Chapter 5: Measurement: Research Using Numbers
Learning Objectives
5-1 Discuss the concept of measurement and its use in communication research.
5-2 Differentiate, with examples, nominal, ordinal, interval, and ratio measurement.
Chapter Summary
This chapter begins by discussing the concept of measurement and its use in communication
Annotated Chapter Outline
I. What Do Your Head Size, Attitudes, and Readability Have in Common?
A. Measurement
1. Numerals are labels.
B. Numbers allow discriminations and generalization
1. Numbers and statistical methods can allow us to generalize with varying levels of
II. An Introduction to Scales
Instructor Resource
Treadwell and Davis, Introducing Communication Research: Paths of Inquiry, 4e
SAGE Publishing, 2020
A. Measuring variance
1. Measurement is the process of finding out whether people/media content has
B. Measurement requires answers to three questions
1. What exactly shall we measure and record?
III. Research NOIR
A. Nominal measurement
1. Nominal measurement is really nothing more than labeling or classification.
B. Ordinal measurement
1. Ordinal measures indicate some level of progression; in some sense, one
C. Interval measurement
1. Interval measure is the assumption of equal intervals between points on a scale.
D. Ratio measurement
1. Ratio scales contain a “true” zero that captures the absence of an attribute.
E. Why do we care?
Instructor Resource
Treadwell and Davis, Introducing Communication Research: Paths of Inquiry, 4e
SAGE Publishing, 2020
1. Data determines what we can or cannot do statistically.
2. Two categories of variables (attributes that vary).
F. NOIR in action
1. Nominal: parent and child.
IV. To NOIR Is Not Enough: Reliability and Validity
A. Reliability
1. Researchers work toward eliminating errors of reliability in measurement.
2. Are variations in data due to variations in the phenomena or instability in our
B. Test-retest
1. Compare results using correlation.
C. Intercoder or observer reliability
1. Two research scenarios that require observer reliability are the observation of
human interaction and content analysis.
Instructor Resource
Treadwell and Davis, Introducing Communication Research: Paths of Inquiry, 4e
SAGE Publishing, 2020
D. Inter-item or internal reliability
1. Inter-item reliability is a check that the individual questions in a question set are
consistent in their results and capture the same concept.
E. Established measures of reliability
1. Established measures reliability is a comparison of the results obtained from the
measure with the results obtained from a known, tested measure.
2. Ways to improve the reliability of measures.
a. Rewording specific questions.
V. Validity
A. Content validity: looks OK
1. A measure has content validity if it matches or covers all aspects of the concept
under investigation.
B. Construct validity: theoretically OK
Instructor Resource
Treadwell and Davis, Introducing Communication Research: Paths of Inquiry, 4e
SAGE Publishing, 2020
1. Construct validity shows a demonstrable agreement between the concept or
C. Criterion validity: tests OK
1. Criterion validity relates your measures to other specific measures in two ways.
D. Who wins in the reliability–validity shootout?
1. An ideal instrument has both reliability and validity.
VI. Two Common Measurement Scales
A. Likert scale
1. Commonly has 5 points, and the response options are always the same—
B. Semantic differential scale
1. Pairs opposite ideas toward a concept or object and invites respondents to
C. Assumptions
1. Assumption of equal distances between points on a Likert or semantic
differential scale.
Instructor Resource
Treadwell and Davis, Introducing Communication Research: Paths of Inquiry, 4e
SAGE Publishing, 2020