Attribute Semantics

It is important to understand the meaning of the attributes:

Spatial and Temporal Semantics

This refers to attributes that describe something about space or time, respectively. For example, an attribute 'region' is categorical and spatial, 'latitude' and 'longitude' are quantitative and spatial, 'order date' is quantitative and temporal.

Sequential, Diverging and Cyclic

These are used to describe the order of attribute values.

A sequential attribute has values in a certain sequence. Ex. age, height, weight.

A diverging attribute is one for which we can determine a middle value (or zero-value) such that all the values above it are greater than it (or positive) and all the values below it are less than it (or negative). Ex. temperature, altitude.

A cyclic attribute has values that repeat in a period of time. Ex. hour, week, year.

Hierarchical Attributes

This refers to attributes that may have an internal hierarchical structure.

Ex. product sub-categories, dates, spatial regions, taxonomies.