Cross-sectional data is tabular data organized around multiple entities, where each row represents one entity and time is not the primary organizing dimension. A baseball dataset is cross-sectional when each row describes one player rather than a measurement sequence. section 17.1
Distinguish it from related data structures:
- Time-series data follows one entity at regular time intervals, commonly with columns for measurement time and value. section 17.1
- Panel data combines multiple entities with repeated observations over time. section 17.1
- A date or year column does not make a dataset time series when it records an entity property, such as a player's birth date or debut year. section 17.1
