Chapter 4

Question 1

Construct validity

Answer 1

the extent to which the measurement or manipulation of a variable accurately represents the theoretical variable being studied. In the case of measurement, is the measure that is used an accurate representation of the variable?

Question 2

Internal validity

Answer 2

the accuracy of conclusions drawn about cause and effect

Question 3

External validity

Answer 3

the extent to which a study’s findings can accurately be generalized to other populations and settings.

Question 4

variable

Answer 4

Any event, situation, behavior, or individual characteristic that varies—that is, has at least two values.

Question 5

operational definition

Answer 5

all of these:

1) Definition of a concept that specifies the method used to measure or manipulate the concept.
2) set of procedures used when you measure or manipulate the variable

Question 6

A variable must have an operational definition to be studied

Answer 6

empirically

Question 7

There are two important benefits in operationally defining a variable

Answer 7

1) the task of developing an operational definition of a variable forces scientists to discuss abstract concepts in concrete terms. The process can result in the realization that the variable is too vague to study. This realization does not necessarily indicate that the concept is meaningless, but rather that systematic research is not possible until the concept
can be operationally defined.
2) help researchers communicate their ideas with others. If someone wishes to tell me about aggression, I need to know exactly what is meant by this term, because there are many ways of operationally defining it. Communication with another person will be easier if we agree on exactly what we mean when we use the term aggression in the context of our research.

Question 8

a very important question arises once a variable is operationally defined

Answer 8

How good is the operational definition? How well does it match up with reality? How well does my average bowling score really represent my skill?

Question 9

four most common relationships found in research

Answer 9

the positive linear relationship, the negative linear relationship, the curvilinear relationship, and no relationship between the variables. These relationships are best illustrated by line graphs
that show the way changes in one variable are accompanied by changes in a second variable.

Question 10

nonmonotonic function

Answer 10

the direction of the relationship changes at

least once. Example: curvilinear

Question 11

monotonic function

Answer 11

a relationship that does not change direction

Question 12

curvilinear relationship

Answer 12

is called an inverted-U.

Question 13

When there is no relationship between the two variables, the graph is simply a

Answer 13

flat line

Question 14

correlation coefficient

Answer 14

A numerical index of the strength of relationship between variables

Question 15

uncertainty

Answer 15

implies that there is randomness in events; scientists
refer to this as random variability in events that occur. Research can reduce random variability by identifying
systematic relationships between variables.

Question 16

he relationship between the variables is stronger when

there is less

Answer 16

random variability

Question 17

nonexperimental method

Answer 17

All of these:

1) relationships are studied by observing variables of interest. This may be done by asking people to describe their behavior, directly observing behavior, recording physiological responses, or even examining various public records such as census data. In all these cases, variables are observed as they occur naturally. A relationship between variables is established when the two variables vary together.
2) Use of measurement of variables to determine whether variables are related to one another. Also called correlational method.

Question 18

experimental method

Answer 18

involves direct manipulation and control of variables. The researcher manipulates the first variable of interest and then observes the response.

Question 19

There are two problems with making causal statements

when the nonexperimental method is used:

Answer 19

1) It can be difficult to determine the direction of cause and effect
2) researchers face the third-variable problem—that is, extraneous variables may be causing an
observed relationship

Question 20

The problem of direction of cause and effect is not the most serious drawback to the nonexperimental
method, however. Scientists have pointed out, for example, that astronomers can make accurate predictions even though they often cannot manipulate variables in an experiment. In addition, the direction of cause and effect is often not crucial because, for some pairs of variables, the causal pattern may operate in
both directions.

Answer 20

For instance, there seem to be two causal patterns in the relationship between the variables of similarity and liking: (1) Similarity causes people to like each other, and (2) liking causes people to become more similar. In general, the third-variable problem is a much more serious fault of the nonexperimental method.

Question 21

third variable

Answer 21

In descriptions of the relationship between two variables, a third variable is any other variable that is extraneous to the two variables of interest. True experiments control for the possible influence of third variables. Are sometimes referred to as extraneous variables

Question 22

confounding variable

Answer 22

A variable that is not controlled in a research investigation. In an experiment, the experimental groups differ on both the independent variable and the confounding variable.

Question 23

If two variables are confounded, they are

Answer 23

intertwined so you cannot determine which of
the variables is operating in a given situation. If income is confounded with exercise, income level will be an
alternative explanation whenever you study exercise. Fortunately, there is a solution to this problem: the
experimental method provides us with a way of controlling for the effects of third variables.

Question 24

independent variable

Answer 24

The manipulated variable

Question 25

dependent variable

Answer 25

the variable that is measured

Question 26

The experimental method

Answer 26

all of these:
1) reduces ambiguity, and thus uncertainty, in the interpretation of results
2) attempts to eliminate the influence of all
potential confounding third variables on the dependent variable. This is generally referred to as control of extraneous variables.

Question 27

Any variable that cannot be held constant is controlled by making sure that the effects of the variable are random. Through randomization, the influence of any
extraneous variables is

Answer 27

equal in the experimental conditions. Both procedures are used to ensure that any differences between the groups are due to the manipulated variable.

Question 28

experimental control

Answer 28

Eliminating the influence of an extraneous variable on the outcome of an experiment by keeping the variable constant in the experimental and control groups.

Question 29

The number of potential confounding variables is infinite, and sometimes it is difficult to keep a variable constant. The most obvious such variable is

Answer 29

any personal characteristic of the participants.

Question 30

randomization

Answer 30

Controlling for the effects of extraneous variables by ensuring that the variables operate in a manner determined entirely by chance.

Question 31

strong internal validity requires an analysis of these three elements

Answer 31

temporal precedence, covariation, and eliminate plausible alternative explanations

Question 32

field experiment

Answer 32

An experiment that is conducted in a natural setting rather than in a laboratory setting.

Question 33

The advantage of the field experiment is that the independent variable is investigated in a natural context. The disadvantage is that

Answer 33

the researcher loses the ability to directly control many aspects of the situation.

Question 34

when researchers have conducted experiments

in both lab and field settings, the results of the experiments have been

Answer 34

very similar

Question 35

Sometimes the experimental method is not a feasible alternative because experimentation would be either

Answer 35

unethical or impractical. Child-rearing practices would be impractical to manipulate with the experimental
method, for example. Further, even if it were possible to randomly assign parents to two child-rearing
conditions, such as using withdrawal of love versus physical types of punishment, the manipulation would be unethical.

Question 36

ex post facto

Answer 36

after the fact. The term was coined to describe research in which groups are formed on the basis of some actual difference rather than through random assignment as in an experiment. It is extremely important to study these differences. However, it is important to recognize that this is nonexperimental research because there is no random assignment to the groups and no manipulation of an independent variable.

Question 37

Participant variables

Answer 37

also called subject variables and personal attributes. are characteristics of individuals, such as age, gender, ethnic group, nationality, birth order, personality, or marital status. These variables are by definition nonexperimental; they cannot be manipulated, they must only be measured. For example, to study a
personality characteristic such as extraversion, you might have people complete a personality test that is
designed to measure this variable. Such variables may be studied in experiments along with manipulated
independent variables

Question 38

A classic example of descriptive research in psychology comes from the work of

Answer 38

Jean Piaget, who carefully observed the behavior of his own children as they matured. He described in detail the changes in their ways of thinking about and responding to their environment. Piaget’s descriptions and his interpretations of his observations resulted in an important theory of cognitive development that greatly increased our understanding of this topic. Piaget’s theory had a major impact on psychology that continues today

Question 39

complete understanding of any phenomenon requires study using multiple methods, both experimental and nonexperimental.

Answer 39

No method is perfect, and no single study is definitive.

Question 40

Researchers select the method that best
enables them to address the questions they wish to answer. No method is inherently superior to another.
Rather, the choice of method is made after

Answer 40

considering the problem under investigation, ethics, cost and time constraints, and issues associated with the three types of validity.