I2 Analyst's Notebook 7 User Guide - ISS Africa -Investigation ...

Appendix B: The i2 Semantic Approach
What are Custom Semantic Types? 0.5
A custom semantic type is a semantic type that you create for a specific
classification, which is typically not catered for in the i2 Semantic Type Library.
While the i2 Semantic Type Library has been developed to include the most
common classifications of real-world items, you have to create a new semantic
type for a specific sub-classification. For example, the Person semantic type is
included in the library, but you have to create a custom semantic type for Pilot. See
Defining custom semantic types on page 363, for general guidelines on creating
and naming custom semantic types.
You can create custom semantic types for use with entities, links, attribute classes
or fields.
When to create custom semantic types
You may decide to create custom semantic types for a variety of reasons.
For example, you have data on different kinds of sporting events. The library
contains an Event entity semantic type, but it does not contain entity semantic
types that would be appropriate to distinguish between different kinds of sporting
events (for example, baseball game, rugby match, and so on.) To ensure that
appropriate semantic types exist in the library so that different sporting events are
distinct on charts or in your data source, you must define custom semantic types
that are derived from the Event entity semantic type.
If it is not necessary to distinguish between different specializations of an entity,
then you can simply assign the appropriate generalized entity semantic type to
your data. For example, suppose your chart or data source contains a list of people
who have attended an annual convention. The library does not contain a
Convention entity semantic type, but you can assign the Event entity semantic
type because your chart or data source contains only one kind of event.
You may want to create a custom property semantic type if you want to assign
multiple values for the same property to a single entity or link. For example,
suppose your data source contains a list of a person's bank accounts numbers,
and you have decided to represent each bank account as a property on the entity,
rather than use bank account entities with links to the person that owns them.
Since a property semantic type can only be added once to each entity semantic
type or link semantic type in a library, you can create specializations of the Account
Number property semantic type so that each occurrence has a unique property
semantic type assignment.
358 i2 Analyst’s Notebook 7 User Guide: Customizing & Analyzing