Span-Based Fact Verification System

A Span-Based Fact Verification System is a fact verification system that is an evidence-based NLP system implementing evidence extraction algorithms to solve span-based fact verification tasks.

• AKA: Evidence-Grounded Fact Checker, Span-Based Claim Verifier.
• Context:
  • It can typically implement Document Retrieval Modules for evidence search.
  • It can typically employ Span Selection Modules for precise evidence.
  • It can typically utilize Verdict Classification Modules based on extracted spans.
  • It can typically maintain Evidence Chains for reasoning path.
  • It can typically provide Verification Reports with highlighted evidence.
  • ...
  • It can often incorporate Neural Retrievers for semantic search.
  • It can often use Cross-Encoders for claim-evidence alignment.
  • It can often implement Aggregation Strategys for multiple evidence.
  • It can often employ Contradiction Detection between evidence pieces.
  • ...
  • It can range from being a Three-Stage Verification System to being an End-to-End Verification System, depending on its architecture design.
  • It can range from being a Keyword-Based System to being a Semantic-Based System, depending on its retrieval method.
  • ...
  • It can process Natural Language Claims against document collections.
  • It can output Verification Verdicts with evidence annotations.
  • It can integrate with Knowledge Bases for fact checking.
  • It can be evaluated by Fact Verification Performance Measures.
  • ...
• Example(s):
  • FEVER Baseline Systems using TF-IDF retrieval and RTE classifier.
  • GEAR System with graph-based evidence reasoning.
  • KGAT System utilizing knowledge graphs for verification.
  • UNC System with BERT-based retrieval and classification.
  • DomainFC System for domain-specific fact checking.
  • ...
• Counter-Example(s):
  • Rule-Based Fact Checkers using pattern matching without learning.
  • Crowdsourced Verification Systems relying on human judgment.
  • Knowledge Base Query Systems checking against structured data.
• See: Fact Checking System, Evidence Retrieval System, Claim Verification System, Explainable NLP System.

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