A database is both a physical and logical grouping of data.

It's the logical groupings of data such as geographical location, customer or product information.

An aggregation hierarchy to indicate potential groupings of data through 'isPartOf' relation-ships.

Categorical data is a grouping of data into discrete groups, such as months of the year, age group, shoe sizes, and animals.

A frequency distribution shows us a summarized grouping of data divided into mutually exclusive classes and the number of occurrences in a class.

Charts in newspapers like The Wall Street Journal contain up to 120 elements on average, allowing readers to compare large groupings of data.

The few studies we have been able to track down usually end up being anecdotal case histories, artificial groupings of data, or otherwise lacking controls and never replicated.

Muenchian grouping is an algorithm for grouping of data used in XSL Transformations that identifies keys in the results and then queries all nodes with that key.