Chapter 3 Flashcards
Variable
An attribute that varies, having at least two levels.
Level
One of the possible variations, or values, of a variable. Also called condition. constant
Constant
An attribute that could potentially vary but that has only one level in the study in question.
Measured Variable
A variable in a study whose levels (values) are observed and recorded. See also manipulated variable.
Manipulated Variable
A variable in an experiment that a researcher controls, such as by assigning participants to its different levels (values).
Construct
A variable of interest, stated at an abstract level, usually defined as part of a formal statement of a psychological theory.
Conceptual Variable
A variable of interest, stated at an abstract, or conversational, level. Also called construct.
Operational Definition
The specific way in which a concept of interest is measured or manipulated as a variable in a study. Also called operationalization, operational variable.
Operational Variable
The specific way in which a concept of interest is measured or manipulated as a variable in a study. Also called operationalization, operational variable.
Operationalize
To turn a conceptual definition of a variable into a specific measured variable or manipulated variable in order to conduct a research study.
Claim
The argument a journalist, researcher, or scientist is trying to make.
Frequency Claim
A claim that describes a particular rate or degree of a single variable.
Association Claim
A claim about two variables, in which the value (level) of one variable is said to vary systematically with the value of another variable.
Correlate
To occur or vary together (covary) systematically, as in the case of two variables. See also correlational study, covariance.
Correlational Study
A study that includes two or more variables, in which all of the variables are measured; can support an association claim.
Positive Association
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.
Scatterplot
A graphical representation of an association, in which each dot represents one participant in the study measured on two variables.
Negative Association
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.
Zero Association
A lack of systematic association between two variables. Also called zero correlation. See also curvilinear association, positive association, negative association.
Causal Claim
A claim arguing that a specific change in one variable is responsible for influencing the value of another variable.
Validity
The appropriateness of a conclusion or decision. See also construct validity, external validity, internal validity, statistical validity.
Construct Validity
An indication of how well a variable was measured or manipulated in a study.
Generalizability
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.
External Validity
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.
Statistical Validity
The extent to which statistical conclusions derived from a study are accurate and reasonable. Also called statistical conclusion validity.
Point Estimate
A single estimate of some population value (such as a percentage, a correlation, or a difference) based on data from a sample.
Confidence Interval (CI)
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.
Margin of error of the estimate
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.
Covariance
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.
Temporal Precedence
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.
Internal Validity
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.
Experiment
A study in which at least one variable is manipulated and another is measured.
Independent Variable
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.
Dependent Variable
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.
Random Assignment
The use of a random method (e.g., flipping a coin) to assign participants into different experimental groups.
