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.