Chapter 3

Question 1

Variable

Answer 1

An attribute that varies, having at least two levels.

Question 2

Level

Answer 2

One of the possible variations, or values, of a variable. Also called condition. constant

Question 3

Constant

Answer 3

An attribute that could potentially vary but that has only one level in the study in question.

Question 4

Measured Variable

Answer 4

A variable in a study whose levels (values) are observed and recorded. See also manipulated variable.

Question 5

Manipulated Variable

Answer 5

A variable in an experiment that a researcher controls, such as by assigning participants to its different levels (values).

Question 6

Construct

Answer 6

A variable of interest, stated at an abstract level, usually defined as part of a formal statement of a psychological theory.

Question 7

Conceptual Variable

Answer 7

A variable of interest, stated at an abstract, or conversational, level. Also called construct.

Question 8

Operational Definition

Answer 8

The specific way in which a concept of interest is measured or manipulated as a variable in a study. Also called operationalization, operational variable.

Question 9

Operational Variable

Answer 9

The specific way in which a concept of interest is measured or manipulated as a variable in a study. Also called operationalization, operational variable.

Question 10

Operationalize

Answer 10

To turn a conceptual definition of a variable into a specific measured variable or manipulated variable in order to conduct a research study.

Question 11

Claim

Answer 11

The argument a journalist, researcher, or scientist is trying to make.

Question 12

Frequency Claim

Answer 12

A claim that describes a particular rate or degree of a single variable.

Question 13

Association Claim

Answer 13

A claim about two variables, in which the value (level) of one variable is said to vary systematically with the value of another variable.

Question 14

Correlate

Answer 14

To occur or vary together (covary) systematically, as in the case of two variables. See also correlational study, covariance.

Question 15

Correlational Study

Answer 15

A study that includes two or more variables, in which all of the variables are measured; can support an association claim.

Question 16

Positive Association

Answer 16

An association in which high levels of one variable go with high levels of the other variable, and low levels of one variable go with low levels of the other variable. Also called positive correlation. See also curvilinear association, negative association, zero association.

Question 17

Scatterplot

Answer 17

A graphical representation of an association, in which each dot represents one participant in the study measured on two variables.

Question 18

Negative Association

Answer 18

An association in which high levels of one variable go with low levels of the other variable, and vice versa. Also called inverse association, negative correlation.

Question 19

Zero Association

Answer 19

A lack of systematic association between two variables. Also called zero correlation. See also curvilinear association, positive association, negative association.

Question 20

Causal Claim

Answer 20

A claim arguing that a specific change in one variable is responsible for influencing the value of another variable.

Question 21

Validity

Answer 21

The appropriateness of a conclusion or decision. See also construct validity, external validity, internal validity, statistical validity.

Question 22

Construct Validity

Answer 22

An indication of how well a variable was measured or manipulated in a study.

Question 23

Generalizability

Answer 23

The extent to which the subjects in a study represent the populations they are intended to represent; how well the settings in a study represent other settings or contexts.

Question 24

External Validity

Answer 24

An indication of how well the results of a study generalize to, or represent, individuals or contexts besides those in the study itself. See also generalizability.

Question 25

Statistical Validity

Answer 25

The extent to which statistical conclusions derived from a study are accurate and reasonable. Also called statistical conclusion validity.

Question 26

Point Estimate

Answer 26

A single estimate of some population value (such as a percentage, a correlation, or a difference) based on data from a sample.

Question 27

Confidence Interval (CI)

Answer 27

A given range indicated by a lower and upper value that is designed to capture the population value for some point estimate (e.g., percentage, difference, or correlation); a high proportion of CIs will capture the true population value.

Question 28

Margin of error of the estimate

Answer 28

In the context of a percentage estimate, an inferential statistic providing a range of values that has a high probability of containing the true population value.

Question 29

Covariance

Answer 29

The degree to which two variables go together. Also one of three criteria for establishing a causal claim, which states that, in a study’s results, the proposed causal variable must vary systematically with changes in the proposed outcome variable.

Question 30

Temporal Precedence

Answer 30

One of three criteria for establishing a causal claim, stating that the proposed causal variable comes first in time, before the proposed outcome variable. See also covariance, internal validity.

Question 31

Internal Validity

Answer 31

One of three criteria for establishing a causal claim; a study’s ability to rule out alternative explanations for a causal relationship between two variables. Also called third-variable criterion. See also covariance, temporal precedence.

Question 32

Experiment

Answer 32

A study in which at least one variable is manipulated and another is measured.

Question 33

Independent Variable

Answer 33

In an experiment, a variable that is manipulated. In a multiple-regression analysis, a predictor variable used to explain variance in the criterion variable. See also dependent variable.

Question 34

Dependent Variable

Answer 34

In an experiment, the variable that is measured. In a multiple-regression analysis, the single outcome, or criterion variable the researchers are most interested in understanding or predicting. Also called outcome variable.

Question 35

Random Assignment

Answer 35

The use of a random method (e.g., flipping a coin) to assign participants into different experimental groups.