Virtual Experience Recommendation via Graph Embeddings

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Solution Overview

Problem

Existing recommendation systems face inefficiencies and lack robustness due to insufficient training data and skewed feature distributions, making it difficult to generate recommendations for new users or experiences.

Innovation Solution

A method is developed to train a machine-learning model by generating user and item embeddings using deep neural networks, forming graphs based on user affinity and interactions, and employing algorithms like random walk and Personalized PageRank to recommend virtual experiences, even with limited user engagement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If deep supervised models are trained using traditional methods, then model accuracy improves, but data requirements and training complexity increase significantly

Engineering Contradiction:
Improverecommendation accuracyVSAvoidtraining data volume
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The system performs preliminary actions by pre-computing user embeddings and item embeddings before the actual recommendation query. User towers and item towers are trained in advance to convert user features and item features into compact embedding representations. This preliminary embedding computation allows the system to make accurate recommendations without requiring extensive real-time data processing, thus reducing the immediate data volume needed during inference while maintaining high recommendation accuracy.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Embeddings serve as an intermediary representation between raw user/item features and final recommendations. Instead of directly comparing raw features which require large amounts of data, the system uses learned embedding vectors as intermediaries. These embeddings capture essential patterns and relationships in a compressed form, enabling accurate recommendations with fewer data requirements. The embedding space acts as a mediator that bridges the gap between limited training data and high-quality recommendations.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If traditional recommendation systems use large amounts of labeled data, then model performance improves, but system complexity and training time increase

Engineering Contradiction:
Improverecommendation robustnessVSAvoidmodel training complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The recommendation system is segmented into distinct modular components: user towers, item towers, embedding generators, and ranking models. Each component has a specific function - user towers process user features, item towers process item features, and they interact through the embedding space. This segmentation allows each module to be trained and optimized independently, reducing overall training complexity while maintaining robust recommendations. The modular architecture enables parallel processing and distributed training, further simplifying the training process.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system changes parameters by transforming high-dimensional user and item features into lower-dimensional embedding vectors through learned transformations. This parameter transformation reduces the complexity of the feature space while preserving essential information. By operating in the embedding space rather than the original feature space, the system achieves robust recommendations with simpler models and reduced training complexity.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If recommendation systems rely on well-known users and experiences, then recommendation quality improves, but adaptability to new users and experiences deteriorates

Engineering Contradiction:
Improverecommendation qualityVSAvoidcold start capability
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The embedding-based recommendation system achieves universality by designing a unified architecture that handles both known and unknown users/items through the same mechanism. The user towers and item towers can process any user or item features regardless of whether they are well-known or new. The embedding space provides a universal representation that works for cold start scenarios (new users/items with limited data) and warm start scenarios (established users/items with abundant data), enabling the system to adapt to any user or item while maintaining recommendation quality.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

For new users or items with limited data, the system creates embedding representations that can be initialized from similar known users or items. By copying or transferring embedding patterns from analogous entities, the system can generate reasonable recommendations for cold start cases. This copying mechanism allows the system to leverage knowledge from well-known entities to bootstrap recommendations for new entities, bridging the gap between cold and warm start scenarios.

Inventive Principle:
Principle #26Copying

Data Source

PatentUS20240177013A1Machine-learning model that recommends virtual experiences based on graphs and clustering
Publication Date: 2024.05.30 ROBLOX CORP
  • US20240177013A1 patent drawing
  • US20240177013A1 patent drawing
  • US20240177013A1 patent drawing

AI summary

A computer-implemented method to train a machine-learning model to recommend virtual experiences to a user. The method includes receiving training data that includes pairs of users and virtual experiences, wherein each user of a pair is associated with user features, each virtual experience of the pair is associated with item features, and each pair includes a virtual experience that a corresponding user interacted with. The method further includes training a user tower of the machine-learning model by: generating first feature embeddings based on the user features in the training data and training a first deep neural network (DNN) to output user embeddings based on the first feature embeddings. The method further includes training an item tower of the machine-learning model by: generating second feature embeddings based on the item features in the training data and training a second DNN to output item embeddings based on the second feature embeddings.