Variables

Module Version

Variable: Anything that has a quantity or quality that varies.

Dependent Variables: Growth of tomatoes and the number of fruits produced.

Independent Variables: Amount of sunlight, water, and nutrients in the soil.

Extraneous Variables: Factors that influence the outcome not manipulated by the researcher (e.g., pests, environmental stressors).

Confounding Variable: An extraneous variable that affects the outcome (e.g., pest infestation).

Quantitative Variables: Numeric variables used in quantitative research.

Discrete Variables: Countable whole numbers (e.g., number of students).

Continuous Variables: Take fractional values (e.g., height, temperature).

Interval: Quantitative variables with equal and meaningful intervals, but no true zero (e.g., temperature).

Ratio: Similar to interval, but with a true zero indicating absence (e.g., age, weight).

Qualitative Variables: Categorical variables not expressed in numbers.

Dichotomous: Two distinct categories (e.g., yes or no).

Nominal: Groups of subjects without order (e.g., blood type).

Ordinal: Ranked variables (e.g., survey ratings).

PPT Version

Variables: Measurable characteristics that change in value (e.g., sex, socio-economic status).

Kinds of Variables

Numerical Variable: Expressed in terms of numbers.

Categorical Variable: Stored into groups or categories.

Continuous Variable

A variable that can take an infinite number of values.

Interval Variable: Measurement with meaningful differences but no true zero.

Ratio Variable: Measurement with meaningful differences and a true zero.

Discrete Variables

Numeric variables with a countable number of values.

Nominal Variable: Scale for labeling variables into classifications.

Ordinal Variable: Depicts the order of variables.

Independent and Dependent Variables

Independent Variable: The cause variable responsible for changes.

Dependent Variable: The result or effect of changes.

Examples:

1. Sleep affects test scores.
Independent: length of time of sleep
Dependent: test score

2. Emotional quotient affects Math Exam performance.
Independent: emotional quotient
Dependent: performance in Math Exam

Antecedent, Extraneous, Intervening Variables

Antecedent Variable: Occurs before independent and dependent variables, may affect relationships.

Extraneous Variable: Not intentionally studied in the experiment.

Intervening Variable: Cannot be observed but explains a cause or association.