Coveo Machine Learning Features

The Coveo Machine Learning (Coveo ML) service currently offers the following features:

For further information on Coveo ML, you can consult the Coveo Machine Learning FAQ.

Automatic Relevance Tuning (ART) Feature

In short, the ART feature learns what search users seek and delivers it.


In more detail, ART analyzes user behavior patterns from many Coveo Usage Analytics (Coveo UA) search visit actions (e.g., query reformulation, clicked results, whether a support case was submitted) to understand which clicked results and content lead to successful outcomes, such as self-service success. It automatically adjusts future search results, so that the best-performing content always rises to the top.

ART excels with popular and ambiguous queries, in which users only enter one or two terms, as well as with paragraph-sized queries expressing long descriptions. ART can handle common typographical errors, and it learns implicit synonyms. When your Coveo index includes secured items, ART queries the index to ensure that it only recommends items which the user performing the query is allowed to access.

In practice, ART boosts the ranking weight of recommended items so that they appear among the top search results. Members with the required privileges can configure and activate ART in just a few clicks.

By default, ART model recommendations are based on the language of the user’s query as well as the search interface in which the query was performed. One model is made per search hub/search tab/language combination.

Items are boosted only if they were clicked in the same search interface as the current query.

You can change this default behavior by modifying the filterFields custom model parameter value with the guidance of Coveo Support.

You can use the JavaScript Search Framework Debug Panel to temporarily highlight, and therefore identify, search results promoted by ART.

Query Suggestions (QS) Feature

The QS feature recommends significantly more relevant queries to users as they type in the search box.


The Coveo ML QS feature:

  • Identifies exact, partial, or fuzzy matches with typed characters anywhere in any individual keyword appearing in any order.

  • Stems query suggestion keywords to remove duplicates.

  • Offers the most relevant recommendations by ranking query suggestions, considering:

    • The number of times the query was performed.

    • The degree to which the query suggestion matches the typed characters.

    • The query performance based on the Relevance Index and Click-Through usage analytics metrics.

  • Only considers queries that were followed by clicked search results a specific number of times (see Reviewing Coveo Machine Learning Query Suggestion Candidates). This prevents infrequent queries from polluting the suggestions.

Members with the required privileges can configure and activate Coveo ML QS in a few clicks. Developers can leverage the feature in the desired search interface.

Event Recommendations (ER) Feature


The ER feature learns from your website user page and search navigation history to return the most likely relevant content for each user in his current session. The results that are returned by the Coveo ML ER service can be included in a search page or in any other web page, such as in a side panel window.

The recommendations can be interpreted as “People who viewed this page also viewed the following pages”.

Your company offers product technical documentation and Q&A content on several public websites for customer end users, administrators, and developers. These websites are configured to send all views to Coveo UA. Your website pages include Recommended Articles side panel windows.

The recommendation algorithm is based on the co-occurrence of events such as view events within a user session. When two events co-occur with unusual frequency within sessions, the algorithm learns that they’re linked. When one event is seen, the model recommends the other.

ER model suggestions are provided based only on the user language, since view events are not logged from a search hub.

Dynamic Navigation Experience (DNE) Feature

Pilot Feature


The DNE feature learns from usage analytics events to pertinently order facets and facet values according to user queries. More precisely, Coveo ML DNE models analyze queries and target specific user behaviors (e.g., clicked results, facet selections) to make the most relevant facets appear at the top for a given query.

Coveo ML DNE models also reorder facet values within a given facet to make the most popular values appear at the top. To do so, the models use the search events performed by previous users, who have selected certain facet values for a specific query.

The Coveo ML DNE feature uses its facet value ranking to boost search results. The model uses the most popular facet values ​​for a certain query and applies query ranking expressions (QREs) to boost the search results whose field values match the values of those facets.

See Deploying Dynamic Navigation Experience.

You’re selling smartphones on your e-commerce website. Before enabling Coveo ML DNE, your search page, powered by the Coveo JavaScript Search Framework, displays facets in the following order when customers search for cellphone:

  • Screen size

  • Storage capacity

  • Price

  • Brand

You enable a Coveo ML DNE model. When your search interface sends a query to the Search API to request facets, the DNE model can modify that query in the query pipeline. It applies insights gained from the analysis of past customer behavior and determines that users are most likely to sort search results using the Brand and Price facets. Your search page now displays facets in the following order:

  • Brand

  • Price

  • Screen size

  • Storage capacity

Before you enabled Coveo ML DNE, the Brand facet displayed its facet values in the following order when customers searched for cellphone:

  • LG

  • Samsung

  • Apple

You enable a Coveo ML DNE model. When your search interface sends a query to the Search API to request facets, the DNE model can modify that query in the query pipeline. It applies insights gained from the analysis of past customer behavior and determines that users are most likely to search for Apple and Samsung smartphones rather than for LG devices. The JavaScript Search Framework now displays the facet values within the Brand facet in the following order:

  • Apple

  • Samsung

  • LG

Since the Coveo ML DNE model determined that customers are more likely to shop for Apple smartphones, the model modifies the user query to boost Apple smartphone result list items.

Coveo JavaScript Search Framework 2.7968 (January 2020)

Since the Coveo JavaScript Search Framework January 2020 release, it’s possible to activate the DNE autoselection feature in your Coveo-powered search interfaces.1

1: You must contact Coveo Support to take advantage of the DNE autoselection feature.

The DNE autoselection feature automatically selects facet values according to the end user query. The feature learns from your end users behaviors to understand which categories are the most relevant according to their current browsing task.

In a Coveo-powered commerce interface, an end user searches for queen sheets. Based on the current context and recorded usage analytics data, the DNE model automatically selects the bedding value from the Product category hierarchical facet.1 This filters out potentially irrelevant products such as queen mattresses, sheets of paper, or albums by the band Queen.

1: You should consider configuring the DynamicHierarchicalFacet component in search interfaces that leverage the DNE autoselection feature.

Required Privileges

By default, members of the Administrators and Relevance Managers built-in groups can view and edit elements of the Models page.

The following table indicates the privileges required to use elements of the Models page and associated panels (see Privilege Management and Privilege Reference).

Action Service - Domain Required access level
View models

Machine Learning - Models

Search - Query pipelines

Edit models

Machine Learning - Models


Search - Query pipelines

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