Schema structure

You can determine the structure of your schema by analyzing your data in terms of item and property types. The schema structure is based on your data model.

Item types form the core of your schema and are created to classify the entities and links your identified in your data model. The following table describes the item types that you can create:

Table 1. Item types
Name Description
Entity type You can create entity types to classify your entities that represent your real world objects. For example, you might create a Person entity type to classify entities that represent specific people in an investigation. When you are adding information about these people, details about a specific person are added to a separate entity of type person within the system. You can assign a semantic type to an entity type to provide it with meaning by identifying the nature of the data.
Link type You can create link types to classify the links you create between your entities. For example, a Car entity type and a Person entity type might be associated with an Owner link type. When you are adding information about the relationship between a car and a person, it is added as a link of type owner within the system. A link type also dictates what types of entities can be at the ends of links of that type. You can assign a semantic type to a link type to provide it with meaning by identifying the nature of the data.
When you create item types, you can also create property and property group types that define information about that item type. The following table describes how property and property group types are used to classify property values for that are found in your data:
Table 2. Property and property group types
Name Description
Property type You can create property types to identify features in entity and link types that might be useful in analysis. Property types are important because they enable comparison of data more effectively by declaring whether they are the same. For example, you can create an Eye Color property type to classify properties in your data that represents different eye colors. The logical type of a property type establishes what type of data can be stored in that property type.
Property group type Property types can be grouped in property group types to organize your data in a way that might help analysis. For example, if you had a Person entity type, you might assign facial features such as Hair Color or Eye Color as property types, and these types could be grouped in a Facial Features property group type.
In addition to creating item, property, and property group types, the following table describes how your schema can define other behavior:
Table 3. Other behavior
Name Description
Labeling scheme Labeling schemes define the property types that are used to identify items.
Grade types You can add grading information to indicate the level of confidence you have in your property values for items. You can create a grading system with appropriate grade types to match the rating system that your organization uses.
Link strengths Link strengths that are set in the schema can be used on all link types. Only one link strength can be set as default. The default link strengths describe the links as being either confirmed, tentative, or unconfirmed, but you can configure the labels and their appearance in the Schema Designer.