Challenges and solutions for Latin named entity recognition

Although spanning thousands of years and genres as diverse as liturgy, historiography, lyric and other forms of prose and poetry, the body of Latin texts is still relatively sparse compared to English. Data sparsity in Latin presents a number of challenges for traditional Named Entity Recognition techniques. Solving such challenges and enabling reliable Named Entity Recognition in Latin texts can facilitate many down-stream applications, from machine translation to digital historiography, enabling Classicists, historians, and archaeologists for instance, to track the relationships of historical persons, places, and groups on a large scale. This paper presents the first annotated corpus for evaluating Named Entity Recognition in Latin, as well as a fully supervised model that achieves over 90% F-score on a held-out test set, significantly outperforming a competitive baseline. We also present a novel active learning strategy that predicts how many and which sentences need to be annotated for named entities in order to attain a specified degree of accuracy when recognizing named entities automatically in a given text. This maximizes the productivity of annotators while simultaneously controlling quality

Event-based Access to Historical Italian War Memoirs

The progressive digitization of historical archives provides new, often domain specific, textual resources that report on facts and events which have happened in the past; among these, memoirs are a very common type of primary source. In this paper, we present an approach for extracting information from Italian historical war memoirs and turning it into structured knowledge. This is based on the semantic notions of events, participants and roles. We evaluate quantitatively each of the key-steps of our approach and provide a graph-based representation of the extracted knowledge, which allows to move between a Close and a Distant Reading of the collection.Comment: 23 pages, 6 figure

hr500k – A Reference Training Corpus of Croatian.

In this paper we present hr500k, a Croatian reference training corpus of 500 thousand tokens, segmented at document, sentence and word level, and annotated for morphosyntax, lemmas, dependency syntax, named entities, and semantic roles. We present each annotation layer via basic label statistics and describe the final encoding of the resource in CoNLL and TEI formats. We also give a description of the rather turbulent history of the resource and give insights into the topic and genre distribution in the corpus. Finally, we discuss further enrichments of the corpus with additional layers, which are already underway

Mining semantics for culturomics: towards a knowledge-based approach

The massive amounts of text data made available through the Google Books digitization project have inspired a new field of big-data textual research. Named culturomics, this field has attracted the attention of a growing number of scholars over recent years. However, initial studies based on these data have been criticized for not referring to relevant work in linguistics and language technology. This paper provides some ideas, thoughts and first steps towards a new culturomics initiative, based this time on Swedish data, which pursues a more knowledge-based approach than previous work in this emerging field. The amount of new Swedish text produced daily and older texts being digitized in cultural heritage projects grows at an accelerating rate. These volumes of text being available in digital form have grown far beyond the capacity of human readers, leaving automated semantic processing of the texts as the only realistic option for accessing and using the information contained in them. The aim of our recently initiated research program is to advance the state of the art in language technology resources and methods for semantic processing of Big Swedish text and focus on the theoretical and methodological advancement of the state of the art in extracting and correlating information from large volumes of Swedish text using a combination of knowledge-based and statistical methods

Systemic-functional linguistics and computation : New directions, new challenges

Peer reviewe

Parsing early and late modern English corpora

We describe, evaluate, and improve the automatic annotation of diachronic corpora at the levels of word-class, lemma, chunks, and dependency syntax. As corpora we use the ARCHER corpus (texts from 1600 to 2000) and the ZEN corpus (texts from 1660 to 1800). Performance on Modern English is considerably lower than on Present Day English (PDE). We present several methods that improve performance. First we use the spelling normalization tool VARD to map spelling variants to their PDE equivalent, which improves tagging. We investigate the tagging changes that are due to the normalization and observe improvements, deterioration, and missing mappings. We then implement an optimized version, using VARD rules and preprocessing steps to improve normalization. We evaluate the improvement on parsing performance, comparing original text, standard VARD, and our optimized version. Over 90% of the normalization changes lead to improved parsing, and 17.3% of all 422 manually annotated sentences get a net improved parse. As a next step, we adapt the parser's grammar, add a semantic expectation model and a model for prepositional phrases (PP)-attachment interaction to the parser. These extensions improve parser performance, marginally on PDE, more considerably on earlier texts—2—5% on PP-attachment relations (e.g. from 63.6 to 68.4% and from 70 to 72.9% on 17th century texts). Finally, we briefly outline linguistic applications and give two examples: gerundials and auxiliary verbs in the ZEN corpus, showing that despite high noise levels linguistic signals clearly emerge, opening new possibilities for large-scale research of gradient phenomena in language chang

OCRonym: Entity Extraction and Retrieval for Scanned Books

In the past five years, massive book-scanning projects have produced an explosion in the number of sources for the humanities, available on-line to the broadest possible audiences. Transcribing page images by optical character recognition makes many searching and browsing tasks practical for scholars. But even low OCR error rates compound into high probability of error in a given sentence, and the error rate is even higher for names. We propose to build a prototype system for information extraction and retrieval of noisy OCR. In particular, we will optimize the extraction and retrieval of names, which are highly informative features for detecting topics and events in documents. We will build statistical models of characters and words from scanned books to improve lexical coverage, and we will improve name categorization and disambiguation by linking document contexts to external sources such as Wikipedia. Our testbed comes from over one million scanned books from the Internet Archive

A Web-Based Tool for Analysing Normative Documents in English

Our goal is to use formal methods to analyse normative documents written in English, such as privacy policies and service-level agreements. This requires the combination of a number of different elements, including information extraction from natural language, formal languages for model representation, and an interface for property specification and verification. We have worked on a collection of components for this task: a natural language extraction tool, a suitable formalism for representing such documents, an interface for building models in this formalism, and methods for answering queries asked of a given model. In this work, each of these concerns is brought together in a web-based tool, providing a single interface for analysing normative texts in English. Through the use of a running example, we describe each component and demonstrate the workflow established by our tool