Use features to boost signal of word list

You can add features to your LUIS app to improve its accuracy. Features help LUIS by providing hints that certain words and phrases are part of an app domain vocabulary.

Review concepts to understand when and why to use a feature.

Add phrase list as a feature

  1. Sign in to the LUIS portal, and select your Subscription and Authoring resource to see the apps assigned to that authoring resource.

  2. Open your app by selecting its name on My Apps page.

  3. Select Build, then select Features in your app's left panel.

  4. On the Features page, select + Create.

  5. In the Create new phrase list feature dialog box, enter a name such as Cities. In the Value box, enter examples of the cities, such as Seattle. You can type one value at a time, or a set of values separated by commas, and then press Enter.

    Screenshot of adding feature (phrase list) Cities

    Once you have entered enough values for LUIS, suggestions appear. You can + Add all of the proposed values, or select individual terms.

  6. Keep These values are interchangeable checked if the phrases can be used interchangeably. Interchangeable phrase list feature serves as a list of synonyms for training. Non-interchangeable phrase list serves as separate features for training (meaning that features are similar but the intent changes when you swap phrases).

  7. The phrase list can apply to the entire app with the Global setting, or to a specific model (intent or entity). If you create the phrase list, as a feature from an intent or entity, the toggle is not set for global. In this case, the meaning of the toggle is that the feature is local only to that model, therefore, not global to the application.

  8. Select Done. The new feature is added to the ML Features page.


You can delete, or deactivate a phrase list from the contextual toolbar on the ML Features page.

Global phrase list applies to entire app

A phrase list should be applied to the intent or entity it is intended to help but there may be times when a phrase list should be applied to the entire app as a Global feature.

On the ML Features page, select the phrase list, then select Make global in the top contextual toolbar.

Model as a feature

An entity can be a feature to an intent or entity.

To add an entity as a feature to an intent, select the intent from the Intents page, then select + Add feature above the contextual toolbar. The list will include all phrase lists and entities that can be applied as features.

To add an entity as a feature to another entity, you can add the feature either on the Intent detail page using the Entity Palette or you can add the feature on the Entity detail page.

Next steps

After adding, editing, deleting, or deactivating a feature, train and test the app again to see if performance improves.