Variables and Their Classifications Lecture

Vocabulary flashcards covering definitions and classifications of variables, their measurement levels, and study types as presented in the lecture.

Variable

Any attribute that can vary or change and may affect the results of a study, assuming numerical or categorical values.

Numerical Variable

A variable whose values represent measurable quantities and answer “how many” or “how much.”

Continuous Variable

A numerical variable that can take fractional (non-whole) positive or negative values, e.g., time or temperature.

Discrete Variable

A numerical variable that takes countable whole-number values only, e.g., number of children.

Interval Level of Measurement

Numerical scale where differences between values are meaningful but zero does not indicate absence of the property, e.g., temperature.

Ratio Level of Measurement

Numerical scale with meaningful differences and an absolute zero indicating absence of the quantity, e.g., weight.

Categorical Variable

A variable whose values describe qualities or characteristics, answering “what type” or “which category.”

Nominal Variable

A categorical variable used solely for labeling with no quantitative value, e.g., eye color.

Ordinal Variable

A categorical variable with categories that can be ranked or ordered, e.g., education level.

Dichotomous Variable

A categorical variable that has exactly two categories, such as yes/no responses.

Polychotomous Variable

A categorical variable with more than two categories, such as eye color with brown, blue, and green options.

Independent Variable

An experimental variable that is manipulated to observe its effect on the dependent variable.

Dependent Variable

An experimental variable that is measured to see the effect of changes in the independent variable.

Extraneous Variable

An uncontrolled variable that may influence the outcome of an experiment, potentially confounding results.

Predictor Variable

A non-experimental variable used to predict scores on another variable (often the criterion variable).

Criterion Variable

The outcome variable that a predictor variable aims to forecast in non-experimental research.

Univariate Study

Research involving the analysis of a single variable.

Bivariate Study

Research involving analysis of the relationship between two variables.

Polyvariate Study

Research that analyzes three or more variables simultaneously.

Socio-economic Status (as a Variable)

An example of a categorical variable describing a person’s economic and social position.