Span-Level Evidence Extraction System

A Span-Level Evidence Extraction System is an information extraction system that is a span identification system implementing span extraction algorithms to solve span-level evidence extraction tasks.

• AKA: Precise Evidence Extractor, Token-Level Evidence System.
• Context:
  • It can typically implement Boundary Detection Modules for span delimitation.
  • It can typically utilize Contextual Encoders for span representation learning.
  • It can typically employ Span Scoring Mechanisms for relevance assessment.
  • It can typically maintain Span Index Structures for efficient retrieval.
  • It can typically provide Span Highlighting Interfaces for user visualization.
  • ...
  • It can often incorporate Pre-trained Language Models like BERT or RoBERTa.
  • It can often use BiLSTM-CRF Architectures for sequence labeling.
  • It can often implement Attention Mechanisms for context modeling.
  • It can often support Multi-Granularity Extraction from token to paragraph levels.
  • ...
  • It can range from being a Rule-Based Span Extraction System to being a Neural Span Extraction System, depending on its implementation approach.
  • It can range from being a Single-Pass Extraction System to being a Multi-Stage Extraction System, depending on its processing architecture.
  • ...
  • It can process Unstructured Texts with annotation requirements.
  • It can output Span Boundarys with confidence scores.
  • It can integrate with Question Answering Systems for answer extraction.
  • It can be evaluated by Span Extraction Performance Measures.
  • ...
• Example(s):
  • SQuAD-Based Extraction Systems, such as:
    • BERT for Question Answering with start-end prediction.
    • BiDAF System for bidirectional attention flow.
  • Clinical Evidence Extraction Systems, such as:
    • Medical Span Extractor for symptom identification.
    • Clinical Trial Extractor for outcome measures.
  • Legal Span Extraction Systems, such as:
    • Contract Clause Extractor for obligation identification.
    • Legal Citation Extractor for precedent references.
  • ...
• Counter-Example(s):
  • Document Classification Systems, which label whole documents not extract spans.
  • Information Retrieval Systems, which return documents not specific spans.
  • Text Generation Systems, which create new text not extract existing spans.
• See: Information Extraction System, Span Identification System, Evidence Extraction System, NLP System.

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