Term Guidelines

OBI Core
Core Classes

Data Modelling

ROBOT Templates

Introduction to OBI data modelling

OBI can be used to provide detailed descriptions of test subjects, their qualities, assays measuring those qualities, and the resulting measurements. Consider this example “John’s mass is 70kg”:


The five ovals in four colors help divide the diagram into broad categories:

Note that although the diagram shows a full set of OBI classes that are potentially connected to John’s mass, reuse of OBI in specific applications may be much simpler, skipping the process modeling part, the value specification part or the datum part.

In the following sections we discuss each oval, the various classes (boxes) and arrows (object properties and data properties) within it.

Material entities and their properties/qualities

Under ‘material entity’ we find OBI’s ‘organism’ class, which has the taxon ‘Homo sapiens’ as a descendant. The dashed arrow between ‘Homo sapiens’ and ‘organism’ indicates that several intermediate classes have been omitted from the diagram. John is an instance of the class ‘Homo sapiens’, which means he is also an instance of ‘organism’ and ‘material entity’.

John has a particular ‘mass’ quality. We link John to his mass quality with the ‘has quality’ object property. This is an “assertion” or “Abox” statement about instances. We could also assert that any instance of ‘material entity’ ‘has quality’ some ‘mass’ – this would be an “Tbox” or “terminology” statement about classes. As an ontology, OBI focuses on Tbox (class-level) statements, and your data that uses OBI terms will usually focus on Abox (instance-level) statements. This diagram focuses on John and his mass and distinguishes the Abox from the Tbox.