Zero-Shot Event Extraction Using Context-Definition Alignment
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Solution Overview
Problem
Existing event extraction models struggle with generalizing to new event types outside their predefined ontologies, leading to inefficiencies and high computational costs, particularly in real-time applications.
Innovation Solution
A three-stage event representation learning framework that includes offline training with context-definition alignment, query-specific warming, and inference, using auto-extracted alignments to encode mentions and definitions into a shared embedding space, reducing inference time complexity to O(N+T).
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional supervised event extraction models are used, then event classification accuracy is improved, but adaptability to new event types deteriorates
Solution Approach 1:
The patent pre-aligns event type definitions with contextual sentences during offline training, building a shared embedding space that captures semantic relationships between events and their contexts. This preliminary alignment enables the model to handle new event types during inference without requiring retraining, as the model can leverage the pre-learned semantic representations to classify events outside the original ontology.
Solution Approach 2:
The model achieves universality by training encoders that can represent both event mentions and event type definitions in a unified embedding space. The same encoder architecture processes both training data and new event types, allowing the system to generalize from known event patterns to unseen event types while maintaining classification accuracy.
2Quantity of substance
If existing event extraction models process all event types, then completeness is improved, but computational cost deteriorates
Solution Approach 1:
The patent segments the event extraction process into distinct stages: offline training with context-definition alignment, query-specific warming, and inference. During inference, the model only processes event types relevant to the query context, rather than evaluating all possible event types. This segmentation reduces computational cost while maintaining coverage of relevant event types through the shared embedding space.
Solution Approach 2:
The model performs partial action by focusing computational resources on event types that are semantically relevant to the input context, rather than exhaustively processing all possible event types. The shared embedding space enables efficient retrieval of relevant event type representations, reducing the effective computational burden while maintaining comprehensive event type coverage for the given context.
3Speed
If real-time event extraction is implemented, then speed is improved, but model accuracy deteriorates
Solution Approach 1:
The patent performs preliminary alignment of event type definitions with contextual sentences during offline training, pre-computing shared embeddings that capture semantic relationships. This preliminary action eliminates the need for expensive real-time alignment computations during inference, enabling fast event extraction while maintaining high accuracy through the pre-learned semantic representations.
Solution Approach 2:
The patent replaces complex mechanical alignment processes with a shared embedding space approach. Instead of performing computationally intensive alignment operations during inference, the model uses pre-computed embeddings that directly represent semantic relationships, substituting the mechanical alignment process with a more efficient vector-based similarity computation that enables real-time processing.
Data Source
AI summary
A zero-shot event extraction model training method, performed by a computer device, includes obtaining from memory a raw text corpus and verbal synsets; extracting event type definitions from the verbal synsets; generating alignment data by aligning sentences from the raw corpus with the event type definitions; training a first encoder, based on the alignment data, to embed target mentions within the sentences into a shared embedding space; training a second encoder to embed the event type definitions into the shared embedding space; and obtaining a zero-shot event extraction model including the trained encoders, the model being configured to receive a sentence including a candidate mention and event type definitions, and output, for the candidate mention, similarity scores corresponding to the event type definitions or a predicted event type label.


