Stats Analysis terms

Observational Study

A study where researchers only observe and measure variables without assigning treatments or manipulating conditions; cannot establish causation.

Experimental Study

A study where researchers assign treatments or manipulate conditions; allows causal inference if random assignment is used.

Explanatory Variable

The variable that is thought to explain or predict changes in another variable; the 'input' or predictor.

Response Variable

The outcome being measured; the variable that responds to changes in the explanatory variable.

Blocking Variable

A variable used to group subjects into similar categories before randomizing treatments, reducing confounding and improving fairness of comparisons.

Confounding Variable

A variable that influences both the explanatory and response variables, making it difficult to determine causal relationships.

Blind Study

A study where participants do not know which treatment they are receiving.

Double‑Blind Study

A study where both participants and outcome evaluators do not know which treatment each participant receives.

Sample

The group of individuals actually observed or measured in a study.

Population

The entire group of individuals the researchers want to draw conclusions about.

Sample Statistic

A numerical summary calculated from the sample (e.g., sample mean).

Population Parameter

A numerical value describing the entire population (e.g., true population mean).

Correlation

A statistical relationship between two variables; does not imply causation.

Causation

A relationship where changes in one variable directly produce changes in another; requires experimental evidence.

Treatment

The condition or intervention applied to subjects in an experiment.

Random Assignment

Assigning subjects to treatments using chance; eliminates confounding and enables causal inference.