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An Ontology, also referred to as a taxonomy or labeling protocol, defines what is being labeled to make the data interpretable by computer vision applications. This structured framework categorizes the types of objects and concepts that are to be identified and annotated within images, videos, audio files, documents, and DICOM files.
For more information on how Ontologies can be structured, see our Ontology structure documentation.

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Nested Attributes

Ontologies support nested attributes on object and classification labels. This allows you to create hierarchical label structures. With nested attributes, you can define parent options that enable child options in a tree-based interface. This is particularly useful for creating complex taxonomies where certain sub-objects or sub-classifications only become relevant after selecting a parent category. For example, you might create a “Quality” classification with options like “Good” and “Bad”, where selecting “Good” enables additional severity options like “Minor” or “Major”. This hierarchical approach helps organize complex labeling workflows and ensures annotators only see relevant options based on their previous selections.
Nested attributes are currently supported for radio buttons in object labels and classification labels.

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Create Ontologies

We recommend learning about Ontology structure in Encord before creating Ontologies.
  1. Click the New ontology button in the Ontologies section to create a new Ontology.
  1. Give your Ontology a meaningful title and description. A clear title and description keeps your Ontologies organized.
  2. Click Next to continue.
  1. Define your Ontology structure. See our documentation on Ontology structure for more information on the various types of objects, classifications, and attributes.
To add objects:
Ensure that you add Audio Region objects for audio files and Text Region objects for text files.
  1. Click the Add object button.
  2. Do one of the following:
    • Select a Shared class
    • Click New Object
    Shared classes cannot be edited while creating an Ontology. To edit a shared class go to the Ontologies > Shared classes page.
  3. To create a new object, give the object a name. For example “Apple”.
  4. Select a shape for the object. For example polygon.
  5. Optionally, enable the Required toggle to mark the object as Required.
  6. Optionally, add attributes to the object.
  7. Repeat these steps for as many objects as necessary.
To add attributes to an object: You can add attributes to objects that define the object’s characteristics. For example the object “Apple” can have an attribute “Color”.
  1. Click the arrow icon next to an object to add attributes to the object.
  2. Give the attribute a name. For example “Color”.
  3. Click the attribute type to change the attribute type. The default attribute type is a text field.
  4. Click Add option to add an option, if you have chosen a radio button or checklist attribute.
  5. Enter a name for the attribute option. For example, the attribute “Color” can have the options “Red”, “Green”, and “Yellow”.
  6. Click the Back to parent button to return the Ontology creation view.
To add a classification:
  1. Click Add classification.
  2. Do one of the following:
    • Select a Shared class
    • Click New classification
    Shared classes cannot be edited while creating an Ontology. To edit a shared class go to the Ontologies > Shared classes page.
  3. For a new classification, give the classification a name. For example, “Time of day”.
  4. Optionally, configure the classification. The default classification type is a text field.
  5. Optionally, enable the Required toggle to mark the object as Required.
  6. Repeat these steps for as many classifications as necessary.
Configure classifications: You can configure classifications to change the classification type, and to add classification options to radio buttons and check lists.
  1. Click the arrow icon next to an object to configure the classification.
  1. Click the classification type to change the classification type. The default classification type is a text field.
  2. Click Add option to add an option if you have selected a radio button or check list classification.
  3. Enter a name for the classification option. For example, the classification “Time of day” can have the options “Night” and “Day”.
  4. Click the Back to parent button to return the Ontology creation view.