Parameter Ensembling for Factual Abstractive Summarization

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Solution Overview

Problem

Neural abstractive summarization systems frequently hallucinate information due to errors in training data, and existing methods to address this issue are inefficient and costly.

Innovation Solution

A document summarization framework called Contrastive Parameter Ensembling (CaPE) that combines parameters from a base model, an expert model, and an anti-expert model, trained on clean and noisy data subsets, to reduce hallucinations while retaining knowledge and diversity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If neural abstractive summarization models are trained on available training data, then the models can generate summaries, but hallucinations occur at high frequency due to errors in training data

Engineering Contradiction:
Improvesummary generation capabilityVSAvoidfactual accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The training data is segmented into clean and noisy subsets. The model is trained separately on clean data to learn accurate summarization patterns, and then fine-tuned on noisy data with correction mechanisms. This segmentation allows the model to distinguish between reliable and unreliable training examples, reducing hallucination while maintaining productivity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system implements feedback mechanisms where the model's generated summaries are evaluated against the original document content. When hallucinations are detected, correction signals are fed back to adjust the model's parameters. This feedback loop continuously improves factual accuracy while preserving the model's ability to generate summaries efficiently.

Inventive Principle:
Principle #23Feedback

2Reliability

If training data is cleaned to remove errors, then hallucination frequency decreases, but the process is time-inefficient and costly

Engineering Contradiction:
Improvefactual accuracyVSAvoiddata preparation time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system employs self-service mechanisms where the model automatically identifies and corrects errors in training data during the training process itself, without requiring external manual cleaning. The model uses its own generated summaries and attention mechanisms to detect inconsistencies and learn from corrected examples, significantly reducing the time and cost of data preparation while maintaining high factual accuracy.

Inventive Principle:
Principle #25Self-service

3Productivity

If all training data is used including noisy samples, then model training is efficient, but hallucination frequency increases

Engineering Contradiction:
Improvetraining efficiencyVSAvoidfactual accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system dynamically changes training parameters such as learning rate, temperature, and attention weights based on the quality of training data being processed. When training on noisy data, the model adjusts parameters to reduce the influence of unreliable examples. This allows efficient use of all available training data while maintaining factual accuracy through adaptive parameter modification.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS20250307532A1Systems and methods for parameter ensembling for reducing hallucination in abstractive summarization
Publication Date: 2025.10.02 SALESFORCE INC
  • US20250307532A1 patent drawing
  • US20250307532A1 patent drawing
  • US20250307532A1 patent drawing

AI summary

Embodiments described herein provide a document summarization framework that employs an ensemble of summarization models, each of which is a modified version of a base summarization model to control hallucination. For example, a base summarization model may first be trained on a full training data set. The trained base summarization model is then fine-tuned using a first filtered subset of the training data which contains noisy data, resulting in an “anti-expert” model. The parameters of the anti-expert model are subtracted from the parameters of the trained base model to produce a final summarization model which yields robust factual performance.