Mallows Model Preference Ranking System

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Solution Overview

Problem

Current methods for learning user preferences rely on restrictive forms of preference data, such as full rankings or top-t items, and are unable to effectively utilize arbitrary pairwise comparisons, which are common in real-world scenarios like web search and product comparison.

Innovation Solution

A computer-implemented method and system that learns probabilistic distributions over user preferences using statistical models, specifically the Mallows model, which infers and ranks preferences based on partial preference information, including pairwise comparisons, to identify and rank options for groups of users.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If restrictive forms of preference data (full rankings or top-t items) are used, then existing statistical models can process the data, but the ability to utilize arbitrary pairwise comparisons is lost

Engineering Contradiction:
Improveability to process arbitrary pairwise comparisonsVSAvoidcomplexity of preference data processing
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent changes the parameter representation from full rankings or top-t items to arbitrary pairwise comparisons. The system learns probabilistic distributions over preferences by modeling pairwise comparison data, allowing flexible representation of user preferences without requiring complete ranking information. This parameter change enables the system to handle diverse preference data formats while maintaining statistical modeling capabilities.

Inventive Principle:
Principle #35Parameter changes

2Quantity of substance

If pairwise comparisons are used, then preference data utilization is improved, but computational difficulty increases

Engineering Contradiction:
Improveamount of usable preference dataVSAvoidcomputational difficulty of learning models
Core Design Contradiction:
Quantity of substanceVSDifficulty of detecting and measuring

Solution Approach 1:

The patent replaces complex mechanical computation with probabilistic statistical modeling. Instead of directly computing with pairwise comparison data using traditional optimization methods, the system uses probabilistic models to represent preferences and infer underlying distributions. This substitution enables handling of large quantities of pairwise comparison data through statistical inference rather than computationally intensive optimization.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system changes the approach by modeling preferences as probabilistic distributions rather than deterministic rankings. By representing preferences as probability distributions over possible rankings, the system can handle pairwise comparison data more efficiently, transforming the computational problem into a statistical inference problem that is more scalable and tractable.

Inventive Principle:
Principle #35Parameter changes

3Loss of information

If partial preference information is used, then data availability is improved, but prediction accuracy may be compromised

Engineering Contradiction:
Improveamount of preference information lostVSAvoidaccuracy of preference prediction
Core Design Contradiction:
Loss of informationVSMeasurement precision

Solution Approach 1:

The system uses feedback from observed pairwise comparisons to iteratively refine probabilistic models of user preferences. By continuously updating the probabilistic distributions based on new comparison data, the system can accurately predict unobserved preferences even when only partial information is available. The feedback mechanism allows the model to compensate for missing data through statistical inference.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes the representation from deterministic preference values to probabilistic distributions. This allows the system to work with partial information by modeling uncertainty explicitly. The probabilistic parameters capture not only the observed preferences but also the uncertainty around unobserved preferences, enabling accurate predictions despite incomplete data.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS9727653B2System and method for identifying and ranking user preferences
Publication Date: 2017.08.08 GOOGLE LLC
  • US9727653B2 patent drawing
  • US9727653B2 patent drawing
  • US9727653B2 patent drawing

AI summary

Methods and systems for learning models of the preferences of members drawn from some population or group, utilizing arbitrary paired preferences of those members, in any commonly used ranking model are disclosed. These methods and systems utilize techniques for learning Mallows models, and mixtures thereof, from pairwise preference data.