Dialogue Policy Optimization via Implicit Feedback Reinforcement Learning

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Solution Overview

Problem

Conventional digital assistant systems rely on hand-crafted rules for policy models, which are time-consuming to develop, inefficient, and do not scale well, leading to inconsistent and inaccurate policy decisions.

Innovation Solution

The use of unsupervised machine learning techniques, specifically reinforcement learning, to optimize policy models by utilizing implicit user feedback, such as user interactions and parameter changes, to determine the success of policy actions and update the reward function, thereby improving the accuracy of policy decisions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If hand-crafted rules are used for policy models, then the system can provide structured control over policy decisions, but the development process becomes time-consuming and the system does not scale well

Engineering Contradiction:
Improvepolicy decision accuracyVSAvoiddevelopment time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system enables self-service by allowing the policy model to automatically learn and optimize dialogue policies through reinforcement learning from implicit user feedback, eliminating the need for manual hand-crafted rule development while maintaining reliable policy decisions

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system implements feedback mechanisms by collecting implicit user feedback (such as user interactions and parameter changes) and using it to continuously optimize the policy model through reinforcement learning, enabling the system to improve autonomously over time

Inventive Principle:
Principle #23Feedback

2Adaptability or versatility

If hand-crafted rules are used for policy models, then the system can maintain consistent control logic, but the complexity increases as the system needs to cover more dialogue scenarios

Engineering Contradiction:
Improvedialogue scenario coverageVSAvoidpolicy model complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system applies parameter changes by representing policies as learnable parameters in a neural network model that can be optimized through reinforcement learning, allowing the system to adapt to diverse dialogue scenarios without manually crafting complex rules for each scenario

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system replaces the mechanical system of hand-crafted rule-based policies with a data-driven reinforcement learning approach, substituting manual rule creation and maintenance with automated learning from implicit user feedback, thereby reducing complexity while improving adaptability

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

3Measurement precision

If explicit user feedback is used to evaluate policy actions, then the system can directly measure user satisfaction, but the feedback may not accurately reflect the user's actual desired goal

Engineering Contradiction:
Improvepolicy evaluation accuracyVSAvoiduser goal alignment
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The system uses implicit user feedback (such as user interactions and parameter changes) as an intermediary indicator that more reliably reflects the user's actual desired goal compared to direct explicit feedback, which may be biased or inaccurate in measuring true user satisfaction

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentUS10810274B2Optimizing dialogue policy decisions for digital assistants using implicit feedback
Publication Date: 2020.10.20 APPLE INC
  • US10810274B2 patent drawing
  • US10810274B2 patent drawing
  • US10810274B2 patent drawing

AI summary

Systems and processes for optimizing dialogue policy decisions for digital assistants using implicit feedback are provided. In an example process, a user utterance is received. Based on a text representation of the user utterance, one or more user intents corresponding to the user utterance are determined. A policy action is selected from a plurality of candidate policy actions based on a belief state for the one or more user intents and a policy model. The policy action is performed, including outputting results of the policy action for presentation. A success score for the policy action is determined based on whether one or more predetermined types of implicit user feedback are detected after performing the policy action. A set of parameter values of the policy model is modified using the determined success score.