LMDX: Language Model-based Document Information Extraction and Localization

Abstract Commentary & Rating

Prof. Otto NomosOct 04, 20232 min read

Published on Sep 19

Authors:Vincent Perot,Kai Kang,Florian Luisier,Guolong Su,Xiaoyu Sun,Ramya Sree Boppana,Zilong Wang,Jiaqi Mu,Hao Zhang,Nan Hua


Large Language Models (LLM) have revolutionized Natural Language Processing (NLP), improving state-of-the-art on many existing tasks and exhibiting emergent capabilities. However, LLMs have not yet been successfully applied on semi-structured document information extraction, which is at the core of many document processing workflows and consists of extracting key entities from a visually rich document (VRD) given a predefined target schema. The main obstacles to LLM adoption in that task have been the absence of layout encoding within LLMs, critical for a high quality extraction, and the lack of a grounding mechanism ensuring the answer is not hallucinated. In this paper, we introduce Language Model-based Document Information Extraction and Localization (LMDX), a methodology to adapt arbitrary LLMs for document information extraction. LMDX can do extraction of singular, repeated, and hierarchical entities, both with and without training data, while providing grounding guarantees and localizing the entities within the document. In particular, we apply LMDX to the PaLM 2-S LLM and evaluate it on VRDU and CORD benchmarks, setting a new state-of-the-art and showing how LMDX enables the creation of high quality, data-efficient parsers.

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The paper titled "LMDX: Language Model-based Document Information Extraction and Localization" aims to address the challenge of extracting structured information from visually rich documents (VRDs) using large language models (LLMs).

Key Takeaways:

  1. Challenge with LLMs: Despite the strides made in natural language processing, LLMs haven't been successful with semi-structured document information extraction due to a lack of layout encoding and grounding mechanisms.

  2. LMDX Methodology: The authors introduce LMDX to adapt LLMs for this specific extraction task. This technique can extract different types of entities, provide the ground-truth source, and even locate these entities within the document.

  3. Successful Implementation: When applied to the PaLM 2-S LLM and evaluated on specific benchmarks, LMDX establishes a new state-of-the-art in the domain, emphasizing its ability to create high-quality parsers with efficiency.

Potential Real-World Impact:

  • Automated Document Processing: Efficient extraction of structured information from documents can revolutionize industries like finance, legal, and healthcare, where there's a constant need to extract data from documents for further analysis.

  • Reduced Need for Manual Annotation: Grounding guarantees can significantly reduce the need for manual oversight to ensure the validity of extracted data.

  • Versatility: The model's ability to handle different types of entities and provide localization within documents gives it an edge in real-world applications where context and location in a document can be crucial.

  • Potential Cost Savings: With high-quality, data-efficient parsers, businesses can reduce costs related to manual data extraction, verification, and correction.


  • Adoption in Legacy Systems: Many industries already have legacy systems in place, so integrating and adapting new methodologies might require time and resources.

  • Data Sensitivity: Documents from fields like finance and healthcare can contain sensitive information. How the model ensures privacy and security would be a concern for its broader adoption.

Considering the profound implications of effective and efficient document information extraction in numerous sectors:

I'd rate the real-world impact of this paper as a 9 out of 10.

If LMDX can consistently provide accurate extractions across a wide array of document types and domains, it can significantly influence businesses that rely heavily on document processing.

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