Statistical Terminology: Data, Context, and Variables

Data: Recorded values whether numbers or labels, together with their context (p. 17).
Data Table: An arrangement of data in which each row represents a case and each column represents a variable (p. 19).
Record: Information about an individual in a database (p. 20).

Context: The context ideally tells who was measured, what was measured, how the data were collected, where the data were collected, and when and why the study was performed (p. 20).
- Who: Identifies the individuals or cases measured.
- What: Identifies the characteristics or variables measured.
- How: Specifies the method or procedure by which data were collected.
- Where: Specifies the geographical or physical location of data collection.
- When: Specifies the time period or temporal frame in which data were gathered.
- Why: Explains the underlying intent, rationale, or objective of the study.

Case: An individual about whom or which we have data (p. 20).
Respondent: Someone who answers, or responds to, a survey (p. 20).
Subject: A human experimental unit. Also called a participant (p. 20).
Participant: A human experimental unit. Also called a subject (p. 20).
Experimental Unit: An individual in a study for which or for whom data values are recorded. Human experimental units are usually called subjects or participants (p. 20).

Population: The entire group of individuals or instances about whom we hope to learn (p. 20).
Sample: A subset of a population, examined in hope of learning about the population (p. 20).

Variable: A variable holds information about the same characteristic for many cases (p. 21).
Categorical (or Qualitative) Variable: A variable that names categories with words or numerals (p. 21).
Nominal Variable: The term "nominal" can be applied to a variable whose values are used only to name categories (p. 21).
Ordinal Variable: The term "ordinal" can be applied to a variable whose categorical values possess some kind of order (p. 22).
Identifier Variable: A categorical variable that records a unique value for each case, used to name or identify it (p. 22).
Quantitative Variable: A variable in which the numbers are values of measured quantities with units (p. 21).
Units: A quantity or amount adopted as a standard of measurement, such as dollars, hours, or grams (p. 21).