Extraction Fields
Extraction fields define what data DocAI Fabric pulls out of each document. They are configured per document class: every class has its own set of fields, and the Extract activity reads a document using the fields defined for its class.
Getting the fields right is the single biggest lever on extraction quality. This article explains the field types, how to open and use the Field Properties dialog, and what every setting in that dialog does.
Field types
| Type | What it captures | Typical use |
|---|---|---|
| Text | A single free-form value. The value types number, date, and boolean are variations of a simple leaf field. | Invoice number, vendor name, date, total |
| Choice | A value picked from a fixed list of allowed options. | Currency, document subtype, status |
| Group | A container that organizes related fields together. It has no value of its own. | An "Address" group holding street, city, and postcode |
| Repeating group (table) | Multiple rows of structured data. Each child field is a column; each row on the document becomes one entry. | Invoice line items, delivery lines |
A repeating group can be laid out in one of three structures, which you set in the dialog:
- List for variable line items, such as invoice rows.
- 2-D Table for a clean rows-by-columns grid.
- Nested for a categorised hierarchy with sub-groups (for example, line items grouped under a category column).
Groups and repeating groups can contain other groups, so you can model hierarchical documents as deeply as the source requires.
Opening the Field Properties dialog
The Field Properties dialog is where you configure an individual field. Open it from:
- The Transaction Viewer (data panel): open a field's menu and choose Properties. For a table, use the table header menu; for a single column, use the column menu's Column Properties.
- Project settings (Extraction Fields): each field or group row has a Properties button.
The dialog header reads Field Properties followed by the field name, and has three tabs: General, Normalization, and Validation. The Normalization and Validation tabs show a badge with the number of rules that involve the field.
Changes on the General tab are applied only when you click Save Changes. Rules on the Normalization and Validation tabs are saved immediately through their own dialogs.
General tab
Field Name
The name shown to reviewers. It is also used as a hint during extraction, so a clear, descriptive name (for example, "Invoice Number" rather than "num1") improves results on its own.
Extract automatically
Controls whether the AI extracts this field.
- On (default): the field is included in the extraction prompt and the model fills it in.
- Off: the field is excluded from extraction. Its value comes from a business rule (for example, a sum of other fields or a catalog lookup) or is entered manually at review.
When it is off, the extraction-specific settings below (description, structure, multi-page) are hidden, because they only steer extraction. For a group or table, turning this off excludes the whole subtree from extraction.
Field Description
An optional instruction that tells the AI how to find and interpret the value. Add a description only when the field name alone is not enough. Good descriptions cover:
- How the field appears in the document.
- Where to find the value on the page.
- Special formatting or variations to expect.
- Related labels or context clues.
- Be specific: "The unique invoice identifier, usually starting with 'INV-'."
- Add location hints: "Usually in the top-right corner of the first page."
- State the expected format: "Date in MM/DD/YYYY format."
- Resolve ambiguity: "The total amount due including tax, not the subtotal."
Two helpers sit alongside the description:
- The AI suggest / improve button (sparkle icon) drafts a description from the field name, or refines the one you have written.
- Add Conditional Description and View All Descriptions let you attach a description that applies only under a specific condition (for example, a particular form year or supplier) without changing the base description. When a condition matches at extraction time, a Modified by policy badge shows which description was applied.
Structure (repeating groups)
For a table, choose how it is laid out on the document: List, 2-D Table, or Nested. This reflects the real layout and informs how the rows are extracted.
Hierarchy roles (nested tables)
For a Nested table, nominate which columns drive the hierarchy:
- Category: the top-level grouping column.
- Subcategory: an optional second-level grouping column.
A column can hold only one role at a time.
Multi-page rows (repeating groups)
The Rows can span multiple pages checkbox controls whether the extractor keeps scanning past a page break. It is on by default: the model is told to scan every page and stop only when no more rows exist. Turn it off for a table you know is confined to a single page.
Choices (choice fields)
Define the options a reviewer may select. Each option is a label you can add, rename, reorder, or remove. Two switches shape behavior:
- Allow multiple selections: the field stores a comma-separated list, and the model is told more than one option may apply.
- Allow empty selection: the control includes an explicit empty option, and an empty value is treated as acceptable.
To set a default value for a choice field, add a Default Value normalization rule (see the Normalization tab). Defaults are not set in the choices list itself.
Default display (groups)
Controls how a group appears when a transaction is first opened in the viewer. Reviewers can still expand or collapse it manually.
- Auto: expanded only when a field inside needs attention (a rule error or low confidence).
- Expanded: always starts open.
- Collapsed: always starts closed.
Reviewer visibility
Controls how the field appears to a reviewer on the review screen. The field is always extracted (or computed) and always included in exports, regardless of this setting. Visibility only affects the review screen.
| Setting | Behavior | When to use |
|---|---|---|
| Editable | Shown and editable by reviewers (default). | Any value the AI extracts. Extraction can be wrong, so extracted values should stay correctable. |
| Read-only | Shown but not editable. | Values owned by a business rule, such as a catalog-lookup record id or a computed total, that should be visible but not edited by hand. |
| Hidden | Not shown to reviewers at all, but still extracted and exported. | Internal or derived values that reviewers do not need to see. |
For a group or repeating group, the setting cascades to everything inside it, and the most restrictive setting wins. To lock a single column of a table without locking the whole table, open Column Properties for that column and set its visibility there.
Never make an extracted value read-only or hidden if a reviewer might need to correct it. Use Read-only and Hidden for values a rule produces, not for values the AI reads off the page.
Field ID
The unique identifier for the field, used in business rules and API references. It is read-only; use the copy button to grab it.
Normalization tab
Normalization rules automatically transform a field's value after extraction, before validation and export. Use them to clean up formatting, standardize values, apply a default, or map values to a canonical form.
Rules can start from a preset or be written as a custom rule, and each can be enabled or disabled independently. Rules run in order; you manage their order in the Workflow settings. A rule backed by a catalog lookup is marked with a Catalog badge.
Validation tab
Validation rules check the extracted data. If a rule fails, the transaction is flagged for human review. Rules are organized by scope:
- Field Level: validates a single field value.
- Document Level: cross-field checks within one document.
- Transaction Level: cross-document checks.
As with normalization, rules can come from presets or be custom, can be toggled on and off, and may use catalog lookups. See Business Rules for the full rule model.
Required vs optional fields, and confidence
Extraction always returns a confidence score per value. Low-confidence values are highlighted in the Transaction Viewer so reviewers can check them quickly. Combine this with validation rules to enforce that critical fields (such as an invoice number or total) are always present and well-formed, and route anything questionable to review.
Related
- Projects: document classes and when to split fields across classes.
- Extract activity: how fields are used at run time.
- Business Rules: normalization and validation, including catalog lookups.