Configure ontology

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How it works

A clean, thoughtful ontology is critical for creating high-quality labeled data with minimal errors and inconsistencies.

Annotation schemas and schema nodes are the two main components of an ontology. Distinguishing between the two can be tricky at first, but a firm understanding can be helpful when you are working with ontologies via the API. It helps to think of annotation schemas as looking inward at themselves and schema nodes as looking outward as others.



Annotation schema

Annotation schemas (previously called featureSchemas) contain all of the information for rendering an annotation of its kind. The annotation schema is the definition of what the annotation is, outside of its relationship to other annotations in the ontology. It holds information such as the annotation name (e.g., "Eel", "Seahorse"), the annotation kind (e.g., "Polygon", "Point"), and the annotation color (e.g., "#CCFF99").

Schema node

Schema nodes contain information regarding the annotation's place in the ontology structure. While it holds no information about how to render the annotation on the screen, it contains all of the information regarding the annotation's place and role in an ontology's hierarchy. The schema node holds information such as children schema nodes, parent schema nodes, the ontology the annotation belongs to, whether it is required, and the annotation schema it references.


You can think of object-type annotations as the kind of annotations you can see on the screen. This includes Bounding boxes, Segmentation masks, NER Entities, and Relationships.


You can think of classification-type annotations as the kind of annotation that is used to classify the entire asset or frame rather than an individual object on the screen.

Nested classification

Classifications can be global (i.e., it applies to the entire asset) or they can be nested within an object-type annotation (i.e., a child of an object-type annotation).


A relationship is a specialized annotation type that connects two annotations and allows you to name that connection.

Follow these guides to learn how to create and modify your project's ontology to meet your labeling needs.

Create a new ontology

When you create a new project, a new ontology is automatically created is and named after the project. By default, that ontology will only be connected to that one project.



Maximum of 1,000 annotation schemas allowed per ontology.

Create an object-type annotation

  1. Click Add object.

  2. Enter a name for your annotation class.

  3. Select the annotation type.

  4. To add a nested classification, click Add classification.

  5. Click Confirm.

Create a global classification

  1. Click Add classification.

  2. Name your classification.

  3. Enter the answer options.

  4. Enable Required to restrict your labelers from submitting until this classification is answered.

  5. Enable Searchable to allow this classification to be searchable in the ontology search bar.

  6. To create a nested classification within a parent classification, click the arrow icon on the answer choice.

Connect to a shared ontology

Follow these steps to connect your project to another ontology.

  1. Select a project.

  2. Go to Settings > Label editor and click Edit.

  3. Use the dropdown at the top to select another ontology.

  4. Click Connect.



Any change to a shared ontology will impact all projects referencing this ontology. This is not reversible.

Copy an existing ontology

  1. Select an ontology from the dropdown menu.

  2. Click the context menu (3 dots) icon in the corner and select Create copy.

  3. Make any necessary changes to the copied ontology. All changes made to the copied ontology will only affect the project you are configuring. Copied ontologies can, later on, be shared.

Rename the ontology

  1. Select a project.

  2. Click on Settings > Label editor. Then, click Edit.

  3. Click on the context menu (3 dots) at the top and click Rename.

  4. Click Rename to finalize the changes.

Note that renaming a shared ontology will rename the ontology for all projects referencing that ontology. A strategic naming convention for your ontologies can make them easier to find in the dropdown list.

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