Modeling Diachrony in Dictionaries

Introduction: The variety of lexical
structures
Lexical data appear in a wide variety of forms. These can
range from basic morpho-syntactic structures (Romary
et al.) intended to be used in language engineering applications
to important editorial projects that cover multiple levels of
lexicographic description: morphological information, syntactic
constructs, sense related information (definitions, examples,
usage notes, etc.) or historical information. Entries can also
vary in their internal organization. Among other factors, the
fundamental choice between an onomasiological (concept to
word) and a semasiological (word to concept) representation
directly impacts on the internal structure of entries, as well as
on the possible choice of descriptors attached to them. From a
computational point of view, this situation prevents the design
of one single data structure that would fit all the possible needs,
whereas one would like to be able to have uniform access to
similar information across heterogeneous lexical sources. This
has been the source of strong debates, leading for instance to
the ubiquitous "Print Dictionaries" chapter of the TEI (Text
Encoding Initiative) that tries to combine structured and
unstructured views of lexical entries. Still, we want to show in
this paper that it is possible to apply coherent modeling
principles to deal with this variety of structures while providing
a precise account of complex sub-components such as
diachronic information as they appear in dictionaries with wide
lexical coverage. Besides, we want to show that such modeling
principles can guide the possible evolution of the TEI towards
a more flexible data for the concrete representation of
dictionaries. Diachronic information in dictionary
entries
We consider diachronic information along the lines of its
modern, large acceptation as "a word's biography"
(Baldinger). As such, it covers both etymological information
in a restricted sense — tracing out origin and primitive
significance of a lexeme in its source language — and historical
notes about successive changes of form and meaning once it
entered into the target language. This type of information can
for instance be found in the Oxford English Dictionary (OED),
in the Deutsches Wörterbuch (DWB) or in the Trésor de la
Langue Française (TLF), for which Figure 1 illustrates the
organization of diachronic information within the
micro-structure of a lexical entry (pamplemousse): here, the
Etymol. et Hist. section, separated from the synchronic
description of the lexeme, consists of two parts, the first one
being dedicated to the lexeme’s history within the target
language (modern French) and the second one to etymology
proper, i.e. origin and word sense in the source language
(Dutch).
Figure 1
Historical Notes
The main objective of the historical notes is to provide
(earliest) written testimony for each of the senses — and
possibly different usages of a sense — with respect to the
synchronic description of the entry. Therefore, temporal
information and quoted source text associated with
bibliographical references play a central role in this section.
Whereas the OED and the DWB realise the projection from
synchronic sense organization explicitly by subordinating
historical notes under sense description, the diachronic part of
the TLF takes up each of the four synchronic senses by a sense
identifier, a date, a quotation and bibliographical reference.
The latter might be complex in case of use of secondary
literature. One may also notice that differences in word spelling
led to two testimonies for sense 1a. Despite the very strict
application of the sense projection principle — which is far
from being applied systematically throughout the dictionary,
as mentioned for example in Hausmann et al. — one may
however notice that the synchronization has not been made
explicit, for example through the use of the same sense
identifiers within the synchronic and diachronic sections.
Etymological Notes
The etymology section of dictionaries is concerned with
the origin and development of the lexeme before entering
into the target language. As a central task, it informs about one
or more etymons and determines the etymological class
(inheritance, loan word, word generation) for the oldest sense
of the lexeme under consideration. As a consequence, it is not
directly related to individual senses in the modern stage of the
considered language. In the example, the etymon for the oldest
sense of pamplemousse (1a), is the Dutch pompelmoes, itself
being a word generated via composition from pompel and
limoes. Although there have been attempts to formalize further
etymological notes (cf. etymological formulas, Ross), they are
generally not subject to well defined organisation principles,
at least in current dictionaries. Additionally to core information
about etymon, etymological notes may indicate bibliographical
sources of the etymological hypotheses and discuss other related
issues (phonetic evolution, concurrent hypotheses, confidence
statements, secondary etymons, testimony of etymons,
intermediate states etc.).
A representational model for
diachronic information
I n the following sections, we apply the main modeling
principles of the LMF (Lexical Markup Framework) project
within ISO committee TC 37/SC 4 to outline the structure of
diachronic information in dictionary entries. Those principles
(Ide & Romary) allow one to combine a meta-model, which
informs the main agreed upon practices within a given field,
with data categories, corresponding to elementary information
units attached to the nodes of the metamodel. In the case of
lexical structures, a metamodel is itself the combination of a
core metamodel (a simple structure organizing a lexical entry
with form related information and a hierarchy of senses) and
lexical extensions, seen as additional modules attached to the
core meta-model. In our case, we will consider what kind of
lexical extensions are needed for both etymological and
historical information.
A Lexical Extension for Etymological
Structure
We propose a basic lexical extension for etymological
notes (Etymology, cf. Figure 2), i.e. a structure that accounts for the description of links to etymons. The Etymology
component may occur at most once for a given lexical entry,
under the assumption that lexical entries are purely polysemous,
excluding homonyms, given that the difference between both
is made upon historical criteria, cf. adresse¹ (TLF). This
etymological information is further structured by means of
Etymological Unit and Etymological Link components.
Etymological Unit components are word forms playing the role
of etymons. As such, they might be characterized by any
existing data category defined for the description of lexical
entries, i.e. lemmata and inflected forms (language,
orthography, sense, part-of-speech, inflectional information
etc.). Two points have to be noticed: first, the coverage of
language should be extended to more fine-grained geographical
and diachronic variants as those currently available from the
ISO 639 series. Second, depending on available resources, all
or part of this information could be recovered by a pointing
mechanism. Etymological Link components stand for the
etymological relation between linguistic units. A link is
basically characterized by an etymological target and an
etymological source, i.e. pointers to external resources,
including lexical entries of the current dictionary and
etymological units previously described. Etymological links
are typed by the etymological class (loan word, inheritance
etc.). They may additionally bear information about the
bibliographical source, confidence level or other type of notes.
The full paper will show how this data structure accounts for
different types of etymological notes in current dictionaries,
including cases of concurrent, popular, secondary and multiple
etymons.
Figure 2
A Lexical Extension for Historical
Notes
The modeling of historical notes can actually be seen from
two complementary and somehow sequentially organized
perspectives. Firstly, we have identified that historical notes
are organized as a hierarchy of sense like objects, which leads
to the simple historical extension depicted in Figure 3.
Figure 3
This extension takes up the sense component that already exists
in the core LMF meta-model, while further characterizing it
with specific dating (/date/) and bibliographic
(/bibliography/) information. Such an extension accounts
for the situations where there is no a priori editorial coherence
between the sense organization in the lexical entry and its
possible counterparts in the historical notes as encountered in,
e.g., the TLFi or the OED. In that case, we can see that we keep
open the possibility to actuate links (/synchronic
reference/) between components of the historical notes
and senses in the main entry. If we want to model a more
controlled editorial project, we suggest to move from the
previous extension to an integrated view (cf. Figure 4), which
directly anchors historical descriptions on the corresponding
senses. Doing so, it would always be possible to externalize
the corresponding information, to derive an autonomous
representation conformant to Figure 3.
Figure 4 Implementation in the framework of
the TEI
The final paper will show precisely how the two types of
structures described above can be implemented using the
latest version of the specification platform of the TEI (ODD
— One Document Does it all; Burnard & Rahtz). In particular,
we will show that, on the one hand, we can extend the scope
of the existing <etym> element from the P4 guidelines, and,
on the other hand, it is necessary to introduce a new element
dedicated to the representation of historical notes, which mimics
the behavior of related entries (sub-structure with a strong
structural analogy to a full entry), combined with dating and
bibliographical descriptors. Depending on the feedback we will
receive from the lexicographic community, these extensions
could be incorporated into the next version (P5) of the TEI
guidelines.
Bibliography
Baldinger, K. "L’étymologie d’hier et d’aujourd’hui."
Etymologie. Ed. R. Schmitt. Darmstadt, 1977.
Burnard, L., and S. Rahtz. "Relaxing with Son of ODD, or
What the TEI did Next." Paper delivered at the Extreme Markup
Languages conference, Montréal (Canada) , 2-6 August 2004.
2004.
Hausmann, F.J., O. Reichmann, H.E. Wiegand, and L. Zgusta,
eds. Wörterbücher. Ein internationales Handbuch zur
Lexikographie. Berlin / New York: Walter de Gruyter, 1990.
Ide, N., and L. Romary. "International Standard for a Linguistic
Annotation Framework." International Journal on Natural
Language Engineering (Forthcoming).
Romary, L., S. Salmon-Alt, and G. Francopoulo. "Standards
going concrete: from LMF to Morphalou." Coling Workshop
on Enhancing and Using Electronic Dictionaries, Geneva, 29
août 2004. 2004.