Introduction

Fredhopper offers three ways to control behavior based on what products in a product list have in common, i.e. how the attribute values are distributed in a navigation or search result. In other words, value distribution triggers evaluate what percentage of the returned results contain a specific attribute or attribute value. You can use a value distribution trigger when configuring the following business rules: campaigns, ranking rules, facets, redirects, and synonyms.

Note: Value distribution triggers are not available for result modifications.

Types of value distribution triggers

Three types of value distribution triggers are available: Coverage, Dominance, and Selection.

Coverage

The Coverage trigger activates a merchandising rule when a minimum or maximum percentage of the search or navigation results either contain the defined attribute or contain a specific value of that attribute.

Example - Facet

You only want to show the facet "heel height" when it is relevant to the search or navigation results. You could achieve this by using the value distribution trigger of the type Coverage in two ways:

1. Configure the facet so that it is only triggered if at least 70% of the search or navigation results are of the category "shoes".
2. Configure the facet so that it is only triggered if at least 70% of the search or navigation results have a value for the attribute "heel height".

Note: Using a value distribution trigger of the type Coverage ensures that the facet "heel height" is triggered under the specified circumstances for both search and navigation results.

Triggering a facet based on the attribute "categories"

1. In the Merchandising studio navigate to Facets and click New.
2. Enter a Name for the facet and select a Scope.
3. Select the trigger Value Distribution.
   
4. Select Coverage as the Value Distribution Type, Categories as the Attribute and choose Specific value.
   
5. Click Select Categories. 
   
   >> A pop-up window opens.
6. Select the category (or multiple categories) that you want to trigger on - in this case Shoes.
7. Select Minimum Coverage and choose 70%.
   
8. Continue to configure a facet with the attribute "heel height" as described in How to Create a Facet.

Triggering a facet based on the attribute "heel height"

1. Follow steps 1-3 above.
2. Select Coverage as the Value Distribution Type, Heel Height as the Attribute and choose Any Value.
3. Select Minimum Coverage and choose 70%.
   
4. Continue to configure a facet with the attribute "heel height" as described in How to Create a Facet.

Example - Ranking Rule

You want to configure a ranking rule that includes full price status for all brands except one. You can use a Coverage value distribution trigger to ensure the ranking rule is only applied when no more than 30% of the search or navigation results belong to this specific brand. 

1. In the Merchandising studio navigate to Rankings > Ranking rules and click New.
2. Enter a Name for the campaign and select a Scope.
3. Select the trigger Value Distribution.
4. Select Coverage as the Value Distribution Type, Brand Name as the Attribute and choose Specific Value.
5. Click Manage Value distribution. 
   >> A pop-up window opens.
6. Select a brand name (or multiple brand names) - in this case Timberland.
7. Select Maximum Coverage and choose 30%.
   
8. Continue to configure the ranking rule as described here. 

Dominance

The Dominance trigger activates a merchandising rule when a minimum or maximum percentage of the results contain a specific attribute value and that value is the most common value in the result set.

Example - Campaign

You want to show a campaign, i.e. a banner promoting summer dresses, only if at least 40% of the results shown in the search or navigation results come from the category "dresses" and "dresses" is the most common category in the results. 

1. In the Merchandising studio navigate to Campaigns and click New.
2. Enter a Name for the campaign and select a Scope.
3. Select the trigger Value Distribution.
4. Select Dominance as the Value Distribution Type, Category as the Attribute and choose Specific Value.
   Note that for value distribution triggers of the type Dominance, you can always only select Specific Value.
5. Click Select Categories. 
   >> A pop-up window opens.
6. Select the category (or multiple categories) that you want to trigger on - in this case Dresses.
7. Select Minimum Coverage and choose 40%.
   
8. Continue to configure the campaign as described here. 

Selection

The Selection trigger activates a merchandising rule when an attribute or specific value for an attribute is selected. Almost all use cases for the Selection trigger can also be achieved with the User Location trigger. However, for categories, the Selection trigger takes into account the category hierarchy. For example, if a campaign is configured to show when the user selects the category "Men" then the campaign will also trigger if the user selects the category "Men > Jeans".