The concept of object class forms the core of the metadata model used within METEOR. An object class (expressed as a singular noun) describes the 'thing of interest', such as a person, organisation, structure or event. Data is being collected about this 'thing'.

Some examples of object classes in METEOR are: Adoption, Cancer treatment, Dwelling, Female, Healthcare provider, Pregnancy, and Training event.

Object classes can also be types, or specialisations, of other object classes. This helps to gather them in conceptually similar groups, which can make finding them easier.

For example, Service episode is an object class – a period of time during which a client receives assistance from an agency. The object classes such as Emergency department stay and Episode of residential care are object classes, which are two types, or specialisations, of the broader Service episode class.

These top level or ‘parent’ object classes can have multiple sub or ‘child’ classes underneath them. In the above example, Service episode is the parent object class, and Emergency department stay and Episode of residential care are the child object classes.

However, a child object class can only be associated with one parent object class. Child object classes inherit all the characteristics of their parent object class, and have their own unique characteristics.

You can find the list of object class specialisations here.