8A- math

Categorical Variables

Variables that describe qualities or groups where mathematical averaging is not meaningful.

Nominal Variables

Unordered categories with no hierarchy, such as blood types or native languages.

Ordinal Variables

Categories with a clear rank or sequence but without measurable numerical differences between ranks.

Numerical Variables

Variables that represent measurable amounts where standard mathematical operations are valid.

Discrete Variables

Numerical variables that arise from counting and take isolated whole values.

Continuous Variables

Numerical variables that arise from measuring and can take any real value within an interval.

Primary Data

Firsthand data gathered directly by the researcher for a specific inquiry.

Secondary Data

Existing data compiled and published by external organizations for another purpose.

Quantitative Variables

Variables that represent amounts that can be measured.

Qualitative Variables

Variables that describe qualities or characteristics.

Identification of Variable Types

Determining if a variable is categorical or numerical based on its characteristics.

Best Methods for Primary Data Collection

Surveys, direct measurements, observations, structured interviews.

Best Methods for Secondary Data Collection

Official censuses, government databases, peer-reviewed publications.

Example of Categorical Variable

Destination airport or Seat class (Economy, Business, First).

Example of Numerical Variable

Seated passenger count or Flight duration.

Ranked Categories Definition

Categories that have a clear order or sequence (e.g., satisfaction ratings).

Unranked Categories Definition

Categories that do not have a meaningful order (e.g., blood types).

Scope of Primary Data

Best suited for novel questions, localized populations, and high experimental control.

Scope of Secondary Data

Best suited for large-scale demographics, long-term trends, and cost-effective research.

Counting vs. Measuring

Discrete variables arise from counting while continuous variables arise from measuring.