Cold-Start Item Recommendation via User Subset Selection

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Solution Overview

Problem

Existing recommendation techniques, particularly Collaborative Filtering (CF), face challenges in estimating user interests for new items or users due to the lack of historical ratings, leading to the 'cold-start problem, where new items or users cannot be effectively evaluated without available transaction history or context data.

Innovation Solution

A method and system for estimating user interests that select a subset of users based on historical interests to minimize an objective function, such as mean square error, to generate estimated interests for all users regarding a new item, using a CF-based interest evaluation engine with components like a user interest retriever, reviewer selection unit, and user interest estimation unit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If Collaborative Filtering techniques are used to estimate user interests, then prediction accuracy for existing items is improved, but the system cannot effectively handle new items or users due to lack of historical data

Engineering Contradiction:
Improveprediction accuracyVSAvoidability to handle new items
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent introduces content information as an intermediary between users and new items. When a new item arrives, the system retrieves content information about the item and uses it to find similar existing items through content similarity comparison. This intermediary approach allows the system to leverage historical user feedback on similar items to make predictions for new items, bridging the gap caused by the cold-start problem.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system pre-computes and stores content information for existing items in advance. When a new item arrives, the content similarity comparison can immediately utilize these pre-prepared content representations to quickly identify similar items and generate predictions, rather than computing everything from scratch.

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If existing techniques leverage new item's attributes and combine with CF model, then cold-start problem is partially mitigated, but the approach requires content or context data that may not be available

Engineering Contradiction:
Improvecold-start handling capabilityVSAvoiddata availability requirements
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system is designed to autonomously handle the cold-start scenario by automatically retrieving content information for new items and performing content similarity comparisons without requiring manual intervention or pre-existing context data. The system self-adapts to new items by leveraging its built-in content analysis capabilities.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent changes the approach from relying on user-specific parameters (historical ratings) to item-specific parameters (content information). By shifting the basis of prediction from user behavior patterns to item content characteristics, the system can handle new users and items that lack historical data.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If a subset of users is selected to minimize objective function, then estimation accuracy for all users is improved, but the selection process increases computational complexity

Engineering Contradiction:
Improveinterest estimation accuracyVSAvoiduser selection complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Instead of computing predictions for all users, the system selectively computes content similarity only for a subset of users whose historical feedback is most relevant to the new item. This partial action approach reduces computational complexity while maintaining prediction accuracy by focusing resources on the most informative user-item relationships.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentUS10699198B2Method and system for cold-start item recommendation
Publication Date: 2020.06.30 YAHOO ASSETS LLC
  • US10699198B2 patent drawing
  • US10699198B2 patent drawing
  • US10699198B2 patent drawing

AI summary

Method, system, and programs for estimating interests of a plurality of users with respect to a new piece of information are disclosed. In one example, historical interests of the plurality of users are obtained with respect to one or more existing pieces of information. One or more users are selected from the plurality of users. Historical interests of the one or more users can minimize an objective function over the plurality of users. Interests of the one or more users are obtained with respect to the new piece of information. Estimated interests of the plurality of users are generated with respect to the new piece of information based on the obtained interests of the one or more users.