Fiammetta Namer

UMLF: a unified medical lexicon for French.

Lexical resources for medical language, such as lists of words with inflectional and derivational information, are publicly available for the English lantuate with the UMLS Specialist Lexicon. The goal of the UMLF project is to pool and unify existing resources and to add extensively to them by exploiting medical terminologies and corpora, resulting in a Unified Medical Lexicon for French. We present here the current status of the project.

Defining and relating biomedical terms: towards a cross-language morphosemantics-based system.

This paper addresses the issue of how semantic information can be automatically assigned to compound terms, i.e. both a definition and a set of semantic relations. This is particularly crucial when elaborating multilingual databases and when developing cross-language information retrieval systems. The paper shows how morphosemantics can contribute in the constitution of multilingual lexical networks in biomedical corpora. It presents a system capable of labelling terms with morphologically related words, i.e. providing them with a definition, and grouping them according to synonymy, hyponymy and proximity relations. The approach requires the interaction of three techniques: (1) a language-specific morphosemantic parser, (2) a multilingual table defining basic relations between word roots and (3) a set of language-independent rules to draw up the list of related terms. This approach has been fully implemented for French, on an about 29,000 terms biomedical lexicon, resulting to more than 3000 lexical families. A validation of the results against a manually annotated file by experts of the domain is presented, followed by a discussion of our method.

Morphosemantic parsing of medical compound words: Transferring a French analyzer to English

PURPOSE Medical language, as many technical languages, is rich with morphologically complex words, many of which take their roots in Greek and Latin--in which case they are called neoclassical compounds. Morphosemantic analysis can help generate definitions of such words. The similarity of structure of those compounds in several European languages has also been observed, which seems to indicate that a same linguistic analysis could be applied to neo-classical compounds from different languages with minor modifications. METHODS This paper reports work on the adaptation of a morphosemantic analyzer dedicated to French (DériF) to analyze English medical neo-classical compounds. It presents the principles of this transposition and its current performance. RESULTS The analyzer was tested on a set of 1299 compounds extracted from the WHO-ART terminology. 859 could be decomposed and defined, 675 of which successfully. CONCLUSION An advantage of this process is that complex linguistic analyses designed for French could be successfully transposed to the analysis of English medical neoclassical compounds, which confirmed our hypothesis of transferability. The fact that the method was successfully applied to a Germanic language such as English suggests that performances would be at least as high if experimenting with Romance languages such as Spanish. Finally, the resulting system can produce more complete analyses of English medical compounds than existing systems, including a hierarchical decomposition and semantic gloss of each word.

A Rule-Based Morphosemantic Analyzer for French for a Fine-Grained Semantic Annotation of Texts

We describe DeriF, a rule-based morphosemantic analyzer developed for French. Unlike existing word segmentation tools, DeriF provides derived and compound words with various sorts of semantic information: (1) a definition, computed from both the base meaning and the specificities of the morphological rule; (2) lexical-semantic features, inferred from general linguistic properties of derivation rules; (3) lexical relations (synonymy, (co-)hyponymy) with other, morphologically unrelated, words belonging to the same analyzed corpus.

Word Formation Rules and the Generative Lexicon: Representing Noun-to-Verb Versus Verb-to-Noun Conversion in French

This paper focuses on the interface between lexical semantics and word formation. These two linguistic domains give us distinct types of intrinsic information on the semantic content of morphologically constructed words. A common formalism, called Morphological Structure Composition Schema (MS-CS), designed within Generative Lexicon Theory (GL), establishes strong links between these domains. It is illustrated in French by the representation of the Noun-to-Verb (NtoV) versus Verb-to-Noun (VtoN) conversion word formation processes. The relevance of this word formation type for lexical semantics is threefold. It consists in a non-conventional, affix-free, and hence uniquely semantics-driven mechanism. It is a topic of interest to the morphology, syntax, and semantics communities. Finally, it is both a productive and frequent phenomenon, observed in several languages. After an overview of linguistic theories related to this phenomenon, an analysis follows based on a large corpus designed to build a frequency-ranked semantics-based typology of NtoV and VtoN conversion. On the basis of such a classification, a unified GL-inspired model is proposed and illustrated through several examples