NLU Model Drift Correction via Periodic Dictionary Retraining

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Solution Overview

Problem

Natural language understanding (NLU) systems face accuracy deterioration due to model drift, especially in response to unexpected external events like natural disasters, where vocabulary and phrase usage change rapidly, leading to potentially dangerous incorrect predictions.

Innovation Solution

A system that regularly analyzes electronic documents, such as web publications, to update an NLU dictionary based on word and phrase frequency, retraining the model to maintain accuracy and adapt to changing language usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the NLU model is trained on historic data, then the model can make predictions using past patterns, but the prediction accuracy deteriorates over time due to model drift

Engineering Contradiction:
Improveprediction accuracyVSAvoidtime since training
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system implements periodic retraining of the NLU model at scheduled intervals (e.g., daily, weekly, or monthly) to refresh the model with recent data patterns. This periodic action prevents accuracy deterioration by systematically updating the model before significant drift occurs, resolving the contradiction between using historic data for predictions and maintaining accuracy over time.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system continuously monitors prediction accuracy and performance metrics, comparing them against thresholds to detect model drift. When drift is detected or at scheduled intervals, the system automatically triggers retraining cycles. This feedback mechanism ensures the model is updated based on actual performance degradation, maintaining accuracy while optimizing retraining timing.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If the model is retrained frequently to maintain accuracy, then prediction accuracy is maintained, but the computational cost and time required for updates increase

Engineering Contradiction:
Improveprediction accuracyVSAvoidmodel update efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

Instead of continuous retraining, the system employs periodic retraining at optimized intervals determined by performance monitoring and drift detection. This approach maintains prediction accuracy while avoiding unnecessary computational waste from overly frequent retraining, thus resolving the contradiction between accuracy maintenance and update efficiency.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system dynamically adjusts retraining parameters such as the time interval between retraining cycles, the proportion of historical data to use, and the triggering thresholds for drift detection. By optimizing these parameters, the system achieves the minimum necessary retraining frequency to maintain accuracy while minimizing computational overhead and maximizing update efficiency.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If the NLU system uses a fixed vocabulary dictionary, then the system operates efficiently with predictable performance, but the system cannot adapt to new words and phrases that emerge during events like natural disasters

Engineering Contradiction:
Improvevocabulary adaptabilityVSAvoiddictionary management complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system pre-processes and analyzes electronic documents to identify emerging words, phrases, and usage patterns before they significantly impact prediction accuracy. By detecting and incorporating these linguistic changes in advance, the system adapts its vocabulary dictionary proactively, maintaining both adaptability to new language and operational efficiency without requiring complex real-time dictionary management.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors usage patterns in electronic documents and feedback from prediction outcomes to identify emerging vocabulary. When new words or phrases exceed usage thresholds, the system automatically updates the dictionary. This feedback-driven approach enables automatic adaptation to language changes while keeping dictionary management complexity low through rule-based automated processes.

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS11562137B2System to correct model drift for natural language understanding
Publication Date: 2023.01.24 BANK OF AMERICA CORP
  • US11562137B2 patent drawing
  • US11562137B2 patent drawing
  • US11562137B2 patent drawing

AI summary

A system retrains a natural language understanding (NLU) model by regularly analyzing electronic documents including web publications such as online newspapers, blogs, social media posts, etc. to understand how word and phrase usage is evolving. Generally, the system determines the frequency of words and phrases in the electronic documents and updates an NLU dictionary depending on whether certain words or phrases are being used more frequently or less frequently. This dictionary is then used to retrain the NLU model, which is then applied to predict the meaning of text or speech communicated by a people group. By analyzing electronic documents such as web publications, the system is able to stay up-to-date on the vocabulary of the people group and make correct predictions as the vocabulary changes (e.g., due to natural disaster). In this manner, the safety of the people is improved.