Services or capabilities described in Amazon Web Services documentation might vary by Region. To see the differences applicable to the China Regions, see Getting Started with Amazon Web Services in China (PDF).

Optimizing a solution for an additional objective

If you use the User-Personalization recipe or Personalized-Ranking recipe, you can optimize an Amazon Personalize solution for an objective in addition to maximum relevance, such as maximizing revenue.

With item recommendation recipes, the primary objective of Amazon Personalize is to predict the most relevant items for your users based on historical and real-time item interactions data. These are the items your users will most likely interact with (for example, the items they will most likely click). If you have an additional objective, such as maximizing streaming minutes or increasing revenue, you can create a solution that generates recommendations based on both relevance and your objective.

To optimize a solution for an additional objective, create a new solution with the User-Personalization recipe or Personalized-Ranking recipe and choose the numerical metadata column in your Items dataset that is related to your objective. When generating recommendations, Amazon Personalize gives more importance to items with higher values for this column of data. For example, you might choose a VIDEO_LENGTH column to maximize streaming minutes or a PRICE column to maximize revenue.

You can use the Amazon Personalize console, Amazon Command Line Interface (Amazon CLI), or Amazon SDKs. For information about using the Amazon Personalize console, see Creating a solution (console).

Guidelines and requirements

Objective requirements are as follows:

For more information about schemas and data types, see Creating schema JSON files for Amazon Personalize schemas.

Balancing objective emphasis and relevance

There can be a trade-off when recommending items based more on your objective than relevance. For example, if you want to increase revenue through recommendations, recommendations for only expensive items might make items less relevant for your users and decrease user engagement and conversion.

To configure the balance between relevance and your objective, choose one of the following objective sensitivity levels when you create the solution:

Measuring optimization performance

When you create a solution version (train a model) for a solution with an optimization objective, Amazon Personalize generates an average_rewards_at_k metric. The score for average_rewards_at_k tells you how well the solution version performs in achieving your objective. To calculate this metric, Amazon Personalize calculates the rewards for each user as follows:

rewards_per_user = total rewards from the user's interactions with their top 25 reward generating recommendations / total rewards from the user's interactions with recommendations

The final average_rewards_at_k is the average of all rewards_per_user normalized to be a decimal value less than or equal to 1 and greater than 0. The closer the value is to 1, the more gains on average per user you can expect from recommendations.

For example, if your objective is to maximize revenue from clicks, Amazon Personalize calculates each user score by dividing total revenue generated by the items the user clicked from their top 25 most expensive recommendations by the revenue from all of the recommended items the user clicked. Amazon Personalize then returns a normalized average of all user scores. The closer the average_rewards_at_k is to 1, the more revenue on average you can expect to gain per user from recommendations.

For more information about generating metrics, see Evaluating an Amazon Personalize solution version with metrics.

Optimizing a solution (Amazon CLI)

You can optimize for an objective only with the User-Personalization or Personalized-Ranking recipe. To optimize a solution for an additional objective using the Amazon CLI, create a new solution and specify your objective details using the optimizationObjective key in the solutionConfig object. The optimizationObjective has the following fields:

The following is an example of the create-solution Amazon CLI command. Replace the solution name, dataset group arn, and recipe arn values with your own.

For optimizationObjective, replace COLUMN_NAME with the numerical metadata column name from the Items dataset that is related to your objective. For objectiveSensitivity, specify OFF, LOW, MEDIUM, or HIGH.

aws personalize create-solution \
--name solution name \
--dataset-group-arn dataset group arn \
--recipe-arn recipe arn \
--solution-config "{\"optimizationObjective\":{\"itemAttribute\":\"COLUMN_NAME\",\"objectiveSensitivity\":\"MEDIUM\"}}"

When your solution is ready, create a new solution version (for an example command see Creating a solution (Amazon CLI)). Once you create a solution version, you can view the optimization performance with the solution version metrics. See Measuring optimization performance.

Optimizing a solution (Amazon SDKs)

You can optimize for an objective only with the User-Personalization or Personalized-Ranking recipe.

To optimize a solution for an additional objective using the Amazon SDKs, create a new solution and specify your objective details using the optimizationObjective key in the solutionConfig object for the solution. The optimizationObjective has the following fields:

Use the following code to create a solution with an additional objective with the Amazon SDK for Python (Boto3) or the Amazon SDK for Java 2.x.

When your solution is ready, create a new solution version (for example code see Creating a solution version (Amazon SDKs)). Once you create a solution version, you can view the optimization performance with the solution version metrics. See Measuring optimization performance.

SDK for Python (Boto3)

To create a solution that is optimized for an additional objective, use the following create_solution method. Replace the solution name, dataset group arn, and recipe arn values with your own.

For optimizationObjective, replace COLUMN_NAME with the numerical metadata column name from the Items dataset that is related to your objective. For objectiveSensitivity, specify OFF, LOW, MEDIUM, or HIGH.

import boto3

personalize = boto3.client('personalize')

create_solution_response = personalize.create_solution(
    name= 'solution name', 
    recipeArn = 'recipe arn', 
    datasetGroupArn = 'dataset group arn',
    solutionConfig = {
        "optimizationObjective": {
            "itemAttribute": "COLUMN_NAME",
            "objectiveSensitivity": "MEDIUM"
        }
    }
)
solution_arn = create_solution_response['solutionArn']
print('solution_arn: ', solution_arn)

SDK for Java 2.x

To create a solution that is optimized for an additional objective, use the following createPersonalizeSolution method and pass the following as parameters: an Amazon Personalize service client, the dataset group's Amazon Resource Name (ARN), a solution name, the recipe ARN, the item attribute, and the objective sensitivity level.

public static String createPersonalizeSolution(PersonalizeClient personalizeClient, 
                                             String datasetGroupArn, 
                                             String solutionName, 
                                             String recipeArn,
                                             String itemAttribute, 
                                             String objectiveSensitivity) {
    
    try {
        OptimizationObjective optimizationObjective = OptimizationObjective.builder()
            .itemAttribute(itemAttribute)
            .objectiveSensitivity(objectiveSensitivity)
            .build();
    
        SolutionConfig solutionConfig = SolutionConfig.builder()
            .optimizationObjective(optimizationObjective)
            .build();

        CreateSolutionRequest solutionRequest = CreateSolutionRequest.builder()
            .name(solutionName)
            .datasetGroupArn(datasetGroupArn)
            .recipeArn(recipeArn)
            .solutionConfig(solutionConfig)
            .build();

        CreateSolutionResponse solutionResponse = personalizeClient.createSolution(solutionRequest);
        
        return solutionResponse.solutionArn();

    } catch (PersonalizeException e) {
        System.err.println(e.awsErrorDetails().errorMessage());
        System.exit(1);
    }
    return "";

SDK for JavaScript v3

// Get service clients and commands using ES6 syntax.
import { CreateSolutionCommand, PersonalizeClient } from
  "@aws-sdk/client-personalize";
  
// create the personalizeClient
const personalizeClient = new PersonalizeClient({ region: "REGION"});

// set the solution parameters.
export const createSolutionParam = {
  datasetGroupArn: 'DATASET_GROUP_ARN',              /* required */
  recipeArn: 'RECIPE_ARN',                           /* required */
  name: 'NAME',                                      /* required */
  solutionConfig: {
    optimizationObjective: {
      itemAttribute: "COLUMN_NAME",           /* specify the numerical column from the Items dataset related to your objective */
      objectiveSensitivity: "MEDIUM"          /* specify OFF, LOW, MEDIUM, or HIGH */
    }
  }
};

export const run = async () => {
  try {
    const response = await personalizeClient.send(new CreateSolutionCommand(createSolutionParam));
    console.log("Success", response);
    return response; // For unit tests.
  } catch (err) {
    console.log("Error", err);
  }
};
run();

Sample Jupyter notebook

For a sample Jupyter notebook that shows how to create a solution that is optimized for an additional objective based item metadata, see the objective_optimization folder of the Amazon Personalize samples GitHub repository