Two-Headed Attention Autoencoder for Recommendation Bias

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Solution Overview

Problem

Existing recommendation systems often suffer from popularity bias, over- or under-recommending content items based on total evaluations rather than personalized user preferences, leading to ineffective suggestions.

Innovation Solution

A two-headed attention fused autoencoder is trained with both user review data and implicit feedback data, using early and late fusion stages with attention mechanisms to generate personalized recommendations, and an NCE decoder is employed to reduce popularity bias by increasing likelihoods for items with observed interactions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If recommendation systems use popular items as basis for recommendations, then the system can generate recommendations easily, but the recommendations become biased towards popular items and lose personalization

Engineering Contradiction:
Improveease of generating recommendationsVSAvoidpersonalization capability
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The recommendation system is segmented into multiple independent components: an autoencoder module for learning user preferences from implicit feedback, a review embedding module for processing explicit review data, and a recommendation generation module. This segmentation allows each component to specialize in processing specific types of data without being dominated by popularity-based biases, enabling both ease of implementation and personalization capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces latent preference vectors as intermediary representations that mediate between raw user interactions and final recommendations. These latent vectors capture personalized user preferences without directly relying on item popularity, serving as a bridge that transforms popular-item-based data into personalized recommendation signals while maintaining system simplicity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If recommendation systems rely on implicit feedback data only, then the system structure remains simple, but the system cannot capture rich user preference information from reviews

Engineering Contradiction:
Improvesystem structure complexityVSAvoiduser preference information
Core Design Contradiction:
Device complexityVSLoss of information

Solution Approach 1:

The patent merges implicit feedback data and explicit review data into a unified recommendation framework. The autoencoder processes implicit feedback while a separate module embeds review text, and both are combined to form comprehensive user preference representations. This merging captures rich user preference information from multiple sources without creating an overly complex system, as the modules share common latent space representations.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of manufacture

If the system increases recommendation likelihoods based on item popularity, then training becomes simpler, but popularity bias is reinforced and personalized recommendations deteriorate

Engineering Contradiction:
Improvetraining simplicityVSAvoidpreference prediction accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

Instead of increasing recommendation likelihoods based on item popularity as in traditional systems, the patent inverts this approach by using the autoencoder to learn user-specific preference patterns from implicit feedback. The reconstruction loss in the autoencoder incentivizes learning meaningful user preferences rather than relying on popularity statistics, thereby improving preference prediction accuracy while maintaining training simplicity through the standard autoencoder objective function.

Inventive Principle:
Principle #13The other way round (Inversion)

Data Source

PatentUS20220058489A1Two-headed attention fused autoencoder for context-aware recommendation
Publication Date: 2022.02.24 THE TORONTO DOMINION BANK
  • US20220058489A1 patent drawing
  • US20220058489A1 patent drawing
  • US20220058489A1 patent drawing

AI summary

A recommendation system uses a trained two-headed attention fused autoencoder to generate likelihood scores indicating a likelihood that a user will interact with a content item if that content item is suggested or otherwise presented to the user. The autoencoder is trained to jointly learn features from two sets of training data, including user review data and implicit feedback data. One or more fusion stages generate a set of fused feature representations that include aggregated information from both the user reviews and user preferences. The fused feature representations are inputted into a preference decoder for making predictions by generating a set of likelihood scores. The system may train the autoencoder by including an additional NCE decoder that further helps with reducing popularity bias. The trained parameters are stored and used in a deployment process for making predictions, where only the reconstruction results from the preference decoder are used as predictions.