Statistics for the Behavioral Sciences by Frederick J. Gravetter, Larry B. Wallnau ISBN 10: 1305504917 ISBN 13: 9781305504912

18 CHAPTER 1 | Introduction to Statistics
2. A research study comparing alcohol use for college students in the United States
and Canada reports that more Canadian students drink but American students drink
more (Kuo, Adlaf, Lee, Gliksman, Demers, and Wechsler, 2002). What research
design did this study use?
a. correlational
b. experimental
c. nonexperimental
d. noncorrelational
3. Stephens, Atkins, and Kingston (2009) found that participants were able to tolerate
more pain when they shouted their favorite swear words over and over than when
they shouted neutral words. For this study, what is the independent variable?
a. the amount of pain tolerated
b. the participants who shouted swear words
c. the participants who shouted neutral words
d. the kind of word shouted by the participants
ANSWERS
1. C, 2. C, 3. D
1.3 Variables and Measurement
LEARNING OBJECTIVES
6. Explain why operational definitions are developed for constructs and identify the two
components of an operational definition.
7. Describe discrete and continuous variables and identify examples of each.
8. Differentiate nominal, ordinal, interval, and ratio scales of measurement.
■ Constructs and Operational Definitions
The scores that make up the data from a research study are the result of observing and
measuring variables. For example, a researcher may finish a study with a set of IQ scores,
personality scores, or reaction-time scores. In this section, we take a closer look at the variables
that are being measured and the process of measurement.
Some variables, such as height, weight, and eye color are well-defined, concrete entities
that can be observed and measured directly. On the other hand, many variables studied
by behavioral scientists are internal characteristics that people use to help describe and
explain behavior. For example, we say that a student does well in school because he or
she is intelligent. Or we say that someone is anxious in social situations, or that someone
seems to be hungry. Variables like intelligence, anxiety, and hunger are called constructs,
and because they are intangible and cannot be directly observed, they are often called
hypothetical constructs.
Although constructs such as intelligence are internal characteristics that cannot be
directly observed, it is possible to observe and measure behaviors that are representative
of the construct. For example, we cannot “see” intelligence but we can see examples of
intelligent behavior. The external behaviors can then be used to create an operational definition
for the construct. An operational definition defines a construct in terms of external