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Understanding Schemas

Common questions this page answers:

  • What is a schema in Bailo?
  • What types of schemas exist?
  • Why do schemas matter?
  • What is RJSF?

Schemas are the foundation of Bailo's governance model. They define the questions and structure of model cards and access request forms, ensuring that every model in your organisation is documented consistently.

This page explains what schemas are and how they work. For step-by-step instructions on creating a schema, see Creating a Schema.

What is a schema?

A schema is a template that defines the questions, structure, and validation rules for model card and access request forms:

  • What questions appear when someone fills in a model card or access request form
  • How those questions are organised into sections and tabs
  • Which questions are required and which are optional
  • What format answers should take (free text, dates, dropdowns, etc.)

When a user creates a model or submits an access request, they select a schema. That schema then generates the form they fill in.

Schema types

Bailo supports three types of schema, each serving a different purpose:

  • Model Card - Defines the structure of model documentation: intended use, training details, performance metrics, limitations, etc.
  • Data Card - Defines the fields for dataset information: size, format, data source, known limitations or biases, etc.
  • Access Request - Defines the form users fill in when requesting access to a model: who is requesting, why, what permissions they need, etc.

How schemas relate to other concepts

Schemas connect to models, review roles, and forms in a structured relationship.

Schema ──defines──> Model Card Form
Schema ──defines──> Data Card Form
Schema ──defines──> Access Request Form
Schema ──attached to──> Review Roles (which roles must approve)
Model ──selects──> Schema (at setup time)
Data Card ──selects──> Schema (at setup time)

When an administrator attaches review roles to a schema, every model that uses that schema will require those roles to be assigned and to approve releases and access requests.

Active vs inactive schemas

Schemas can be toggled between active and inactive states without breaking existing models:

  • Active schemas appear in the selection list when users create new models or access requests
  • Inactive schemas are hidden from the selection list but continue to work for models that already use them

This allows you to retire old schemas without breaking existing models.

Why schemas matter

Without schemas, every model would be documented differently, making it difficult to:

  • Compare models against each other
  • Ensure governance requirements are met
  • Automate compliance checks
  • Maintain consistent quality across your model inventory

Schemas give administrators control over what information is captured, while giving model owners a clear and structured form to fill in.

Schema versioning and migrations

Schema migrations allow model card data to be transformed when schemas are updated.

As your organisation's requirements evolve, you may need to update schemas. Rather than forcing model owners to re-enter all their information, Bailo supports Schema Migrations - plans that transform model card data from one schema version to another.

See Schema Migrations for details.

Technical details

Schemas are built using JSON Schema and rendered using RJSF (React JSON Schema Form). This means schemas support:

  • Simple text fields, numbers, and dates
  • Dropdown selections and radio buttons
  • Conditional fields that appear based on other answers
  • Multi-section forms with tab navigation
  • Required field validation

For technical instructions on writing schema JSON, see Creating a Schema.

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