Verbs in specialised corpora : from manual corpus - CLILLAC-ARP
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1. gt enrober de calcite mat riaux In the above examples a noun focus alone will not allow a proper analysis of the sentence as in a it leads to identify as a potential term Linux kernel on a CD ROM though the preposition on depends on the verb boot the same applies to c des mat riaux is the direct object of enrober the determiner des depends on the verb enrober and not calcite In this context adopting a verb approach obviously reduces the generation of invalid terms Linux kernel on a CD ROM calcite des mat riaux its correlate being the necessity to deal with verb structures Reason 3 Syntactic verb contexts are very productive for the distributional analysis as they enhance the grouping of words and phrases appearing in similar syntactic contexts which is used in our tool for the construction of semantic classes to produce gt fbasalt crust flow lava magma to generate In the above example the nouns basalt crust flow lava magma are said to form a cohesive semantic class on the basis that they share similar contexts with the verbs produce and generate In designing Syntex a corpus based parser used to generate lexical resources from specialised corpora Bourigault and Fabre 2000 have taken those three parameters into consideration and have extended automatic extraction to verbs and verb phrases 4 2 Syntex a corpus based parser adapted to verb extraction Syntex is a corpus based parser used to2. human and machine In H Somers ed Proceedings of the EAMT workshop on MT Manchester UMIST pp 155 162 K bler N Foucou P Y to appear Teaching English Verbs With Bilingual Corpora Examples in the Computer Science Area in S Granger amp S Petch Tyson ed Contrastive Linguistics and Translation Studies Rodopi Amsterdam L Homme M C 1993 Le verbe en terminologie du concept au contexte L actualit terminologique 26 2 17 19 L Homme M C 1998 D finition du statut du verbe en langue de sp cialit et sa description lexicographique Cahiers de lexicologie 73 2 125 148 Le Moigno S Charlet J Bourigault D Jaulent M C 2002 Terminology extraction from text to build an ontology in surgical intensive care in Proceedings of the AMIA 2002 annual symposium American Medical Informatics Association San Antonio USA Pearson J 1998 Terms in Context Amsterdam John Benjamins Publishing Company
3. need for automating processes that have been tested by linguists Section 3 describes the methodology applied for corpus based manual description highlighting the value of the resulting linguistic information but also the weight of such a heavy and time consuming task 3 Corpus based manual description 3 1 Methodology Using a concordancer allowing perl like regular expressions on a corpus that was not POS tagged we extracted all entries that could be verbs Heuristics were applied to extract verb candidates such as words ending in ing or ed preceded by auxiliaries modals and to A concordance was then processed for each verb in English As the English and French HOWTOs are aligned in the concordancer interface we studied the French equivalents for each English verbal occurrence As will be shown one English verb term may have several French translations that not always depend on different uses but also vary depending on the translator The concordances allowed us to analyse the syntactic contexts of the verbs identifying the arguments in the different syntactic positions in order to build semantic classes The theoretical and methodological approach we used as a tool to analyse verb structures is based on the lexique grammaire which describes each verb via a basic sentence and divides them into classes according to their basic structures and their common transformational and distributional features However corpus observations s
4. put aside for a long time Only in recent years have terminologists and lexicographers started to study the issue of defining verbs as terms for lexicographic descriptions term base creation or ontology building Therefore studies of verbs as terms have been sparse until now However the need for categorising verbs as terms has slowly emerged with the growing use of electronic corpora in term extraction and phraseology description Potential applications of term bases have raised the hypothesis that terms were not only nouns as the rule was in the W ster and domineering approach A textual terminology approach developed by Bourigault and Slodzian 1999 and based on the use of electronic corpora opened the way for such questioning Descriptions of Language s for Specific Purpose s LSPs hardly consider the status of verbs This is particularly true of the Computer Science CS field one of the most frequent LSP taught in France Numerous textbooks provide students with a description of CS English However the description focuses on noun terminology multi word nouns are for instance widely described and on specific grammatical features used in CS English such as the passive or comparison Very few attention is dedicated to the sentence i e to verbs and their distributional and transformational properties Specialised dictionaries or bilingual glossaries mostly focus on nouns When verbs are mentioned they are usually described as de
5. really understand the HOWTOs and make best use of those This corpus is a good example of what must be really dealt with i e texts that more closely reflect the performance aspect of the language than the competence of the ideal hearer speaker Although analysing the HOWTOs do not really mean studying the performance of the speakers the circumstancial characteristics of the communication situation are lost in written texts some typical performance features can be detected such as typos However ill formed words or sentences and the use of various types of translations for the English terms cannot be explained only by performance mistakes Hymes approach of communicative competence is best adapted here to justify the non standard linguistic structures and translations that are observed Any application based on the chomskyan definition of competence will not be able to correctly deal with this kind of texts 2 2 From corpus based manual description to automatic analysis As mentioned above term extraction has become a key issue in language industry because of the increasing need for corpus based multilingual databases or ontologies Corpus based manual description have allowed linguists and language professionals to unveil actual language behaviour and to dispose of real and statistical language data However corpus based manual description requires an investment in time and energy that industry cannot afford Hence the raising
6. system that successfully runs under Win32s Win95 Win NT syst me ANS FORTH 32 bit libre qui fonctionne sous Win32s Win95 Win NT No runs at with Ni with No Nhum Ni applications Prep at with N2 gt N hum 6 Generally the PCI runs at 33MHz En g n ral le PCI tourne a 33MHz A causative construction is possible in French with the introduction of the operator faire 7 You can run Linux on any Alpha based machine Vous pouvez faire tourner Linux sur n importe quelle machine Alpha Comparing those examples with general English uses can help isolate technical contexts The structures described above do not exist in general English on the other hand there are structures in general English that cannot be used in CS English as in become a presidential concern about running for re election in 1996 or stamps old coins and odd documents run around the square The same does not apply to French tourner as in quatre poules blanches tournant en rond sur une place de village since the structure is similar to the specialised use There are other examples in general French that are not in use in CS French such as Quant au cachet de Barbra Streisand il tourne autour de 20 millions de dollars The drawback of this kind of description is that it does not explicitely shows the different structure combinations that are possible as will be shown in section 4 Another significant example is the verb boot To boot is quite frequent in th
7. to boot the notebook with a kernel Une bonne id e serait de d marrer le portable avec un noyau 3 In order to have LILO boot Linux from OS 2 Boot Manager Afin que LILO lance Linux a partir du gestionnaire de d marrage d OS 2 4 You can boot off of a floppy disk Vous pouvez d marrer a partir d une disquette PP deletion allowing a transitive sub structure with arguments restrictions can be found As to boot is an ergative verb an intransitive structure in which the subject argument is can be analysed as the patient affected by the action is allowed In this case the French equivalent is a pronominal structure which is very often used to translate English passives 5 When Linux boots it is usually configured not to produce Quand Linux se lance il n est habituellement pas configur pour produire An intransitive structure with to and into has been found in the corpus 6 Your BIOS may not allow you to boot directly to a SCSI drive Votre BIOS ne vous permettra peut tre pas de d marrer directement a partir d un disque SCSI The syntactic and semantic properties described above show the difference between the neologism to boot and the general verb that has no etymological relationship with the specialised one The general verb behaves very differently Here are two examples extracted from one year of the Herald Tribune that speak for themselves In early 1988 the Saudis booted out Hume A Horan eating habits unde
8. Some results gt such as hesitations cuts repeated segments of a sentence that are typical of spoken situations such as a characters inversion b missing character or c replaced character e g a vebr b veb or c vern for verb 5 see Hymes D 1972 On Communicative Competence in J B Pridde and J Holmes eds Sociolinguitics Selected Readings Baltimore Penguin see Gross M 1975 M thodes en syntaxe Paris Hermann Let us take the description of the verb to run Reference manuals give very few indications on its various uses Dictionaries of computing do not mention it The Merriam Webster s gives only one use which is related to computing to run a problem through a computer This use is also mentioned in the Collins Cobuild but along with another one You don t need a degree in mathematics to run operate a computer A quick check in the HOWTOs and RFCs corpora yielded only four occurrences of run something through in the HOWTOs and none in the RFCs Moreover the arguments of to run do not match with the ones found in the dictionaries Dictionaries To run a problem through a computer Corpus If you run your file through TeX program Bilingual dictionaries gave us the following translations ex cuter passer fonctionner tre en marche and utiliser Manually analysing the occurrences of to run in the corpus showed us that there are other translations in use The information that could not be
9. Verbs in specialised corpora from manual corpus based description to automatic extraction in an English French parallel corpus Natalie K bler CIEL Universit Paris 7 Denis Diderot 2 place Jussieu F 75251 Paris Cedex 05 kubler ccr jussieu fr C cile Fr rot ERSS UMR 5610 Universit de Toulouse Le Mirail 5 all es A Machado F 31058 Toulouse Cedex frerot univ tlse2 fr This paper tackles the issue of verbs in specialised corpora in the view of term extraction Corpus based manual descriptions to be used in various applications have highlighted the deviant uses of verbs in specialised corpora compared with general uses as well as the need for verb extraction However very few attention has been given to verbs both in the terminology theory and automatic term extraction In the light of a manual corpus based description we investigate the status of verbs in an English French highly specialised parallel corpus and advocate a verb oriented analysis in the framework of a corpus based parser adapted to verb extraction Section deals with the status of verbs in the terminology theory section 2 introduces the framework of the experiment and focuses on the characterisation of the parallel corpus in the domain of Computer Science Section 3 is dedicated to the corpus based manual description Finally section 4 introduces a corpus based automatic analysis 1 Status of verbs In the terminology theory the status of verbs has been
10. ction Manual descriptions in LSPs highlight the deviant uses that are not found in the general language However manual corpus work being time consuming and since the need for exhaustive linguistics description has increased automating linguistic information extraction will enable linguists and language professionals to go further in research and applications The approach implemented in Syntex indeed takes into account the LSPs specificities highlighted by corpus based manual descriptions As the use of machine translation has developed in the recent years bilingual term extraction will be more and more needed to build MT specialised dictionaries in order to improve translation results Verb term extraction can also prove very useful in computer assisted language learning CALL leading to automated exercise generation and helping in the correction process Future work will deal with the complete bilingual extraction of verb terms from the HOWTO corpus in order to test the creation and validity of MT dictionaries References Basili R Pazienza M T Vindigni M 1999 Adaptative Parsing and Lexical Learning Actes de VEXTAL 99 Venise Basili R Pazienza M T Vindigni M 1997 Corpus driven Unsupervised Learning of Verb Subcategorization Frames Actes du 5 congr s AI IA 97 M Lenzerini ed Lecture Notes in Artificial Intelligence 1321 pp 159 170 Bourigault D 1994 Lexter un logiciel d extraction de terminologie Application a l acquisi
11. ds RMI FR L API Java associ e aux fonctionnalit s ISAM c tree Plus permet des fonctionnalit s Java au travers de m thodes natives RMI The English HOWTOs the source texts do not show the consistency and quality one can find in texts written by technical writers The syntax is sometimes shaky as is the idiomaticity of some documents written by non native speakers No guideline such as simplified English has been used to avoid ambiguities such as e g cable and ADSL connection instead of cable connection and ADSL connection The French translations are not made by language professional either but by experts in the field The translations are not consistent with each other providing thus several different translations for the same use of one term As the translations are made by different people who are not professional translators they can widely differ As is often the case among French computer scientists inside their work environment English terms are used instead of the recommended French translation cf expert FR disquette de boot for EN boot disk instead of FR disquette d amorce Another common feature consists in using the English verb and adding a French verbal suffix instead of using the French equivalent as the following examples show English verb term French verb term equivalent English verb with French suffix to telnet se connecter par telnet One must be familiar with Linux or at least UNIX systems to
12. e corpus around 700 occurrences However general and even specialised dictionaries give little information on this verb In the on line Merriam Webster s only general uses of to boot can be found to avail to profit The Collins Cobuild offers 7 FOLDOC A Glossary of Computing Terms Dictionary of Computing For Learners of English 8 http www m w com no verb entry for to boot Wordnet provides some information on the specialised use of the verb n 2 below but with very little syntactic semantic information 1 Boot kick give a boot to 2 boot cause to load an operating system and start the initial processes The basic structure of the verb as analysed in the corpus has three syntactic positions that can be filled in by specific arguments The subject is the agent of the action No boots N Prep N gt with the following argument classes N Nhum or applications such as LILO which work as a metaphor as they can be attributed the agent role N operating system system disk bootdisk hard disk floppy disk kernel gt all bootable objects e N CD CD ROM D C A file emergency disk gt booting objects Three prepositions are possible with that structure off with from An idiosyncratic use of the phrasal verb to boot off has been detected 4 1 To boot one of your old kernels off the hard drive Pour lancer l un de vos vieux noyaux partir du disque dur 2 A good idea might be
13. et au NomUrl http www eleves ens fr though it does not cover all of them Let us mention also a few more general tagging errors regarding for instance ambiguous ing forms in English Taken as a whole it should be pointed out that the pre processing quality from sentence segmentation to morphosyntactic tagging obviously impacts on the lexico syntactic analysis 4 3 2 Verb parsing output We will now more closely look at the verb analysis through PP attachment performed by the parser and emphasise on an English verb sample boot compile configure dump mount run which we believe to best represent the endogenous procedures as well as the type of verbs found in specialised corpora In Section 3 we showed that the manual corpus based description highlighted idiosyncratic uses of those verbs compared with their general uses thus implying the need to use automatic tools that adapt to corpora Therefore what we intend to show here is that endogenous procedures are particularly well adapted to corpora as they respect their specificities and use no other information but that of the corpus 17 General as opposed to specific to the HOWTO corpus As mentioned earlier our tool relies on endogenous techniques and more precisely on the corpus productivity implying lexico syntactic redundancy Let s analyse the verb run in the corpus which gets constructed with a wide variety of prepositions as shown below ability to run dif
14. ferent programs in different virtual terminals at the same time other subsystems DRAM for example will run asynchronously at lower clock rates you can run any other program from within emacs can run the PCI at any frequency the above tests were run with some of the special Cyrix Run dosemu with partition access your application which would probably run under the IBCS2 emulator to run dosemu inside a color xterm gt a and runs on all platforms gt b VirtuF lex runs on standard Unix workstations with 8 MB of RAM minimum gt c why not run you NIS slaves on a Linux box gt d to run popular Windows applications on Linux based system software Among all the verb occurrence frequency run is one of the highest in the corpus with approximately 400 occurrences The more occurrences in the corpus the more chances for our tool to find unambiguous cases a b used to resolve ambiguous cases c d The same remarks apply to the following verbs compile configure dump mount which get constructed with various prepositions and whose number of occurrences respectively 224 190 50 115 is high enough to allow the parser to resolve PP attachment ambiguity The table below shows the verb preposition associations and highlights some idiosyncratic uses and missing dictionary based descriptions such as dump back to compile in support compile in support for cross compile from to which the manual verb description had indeed revealed P
15. found in the dictionaries included syntactic and semantic properties Translation inconsistencies are also noticeable in the corpus as different French verbs are used for the same English term without any linguistically motivated reason To run shows a basic syntactic structure with three arguments that does not exist in general English Two French equivalents are possible No runs N Pr p N gt lt gt Np lance ex cute Ni Pr p N gt No Nhum applications that boot such as LILO N command name programme N machine platform programme operating system 1 as the ability to run different programs in different virtual terminals comme la possibilit de lancer des programmes diff rents dans diff rents terminaux virtuels 2 It just runs a command which could be any Linux sound system Il ne fait qu ex cuter une commande qui pourrait tre n importe quel programme de son sous Linux 3 So you write 32 bit code that runs in 16 bit mode on a 32 bit CPU vous crivez donc du code 32 bits qui s ex cute en mode 16 bits sur un processeur 32 bits Arguments can change depending on the preposition Noruns on N with No applications operating system Linux Win95 X Window N machine platform PC 21066 operating system 4 VirtuF lex runs on standard Unix Workstations VirtuFlex tourne sur des stations Unix standard No runs under N with No applications N operating system 5 ANS FORTH
16. generate specialised lexical resources such as lexicons for translation ontologies or thesauri and has been used in various real world applications among the most recent are Bourigault and Lame 2002 Le Moigno et al 2002 Chodkiewicz et al 2002 Syntex first identifies lexico syntactic dependencies in the sentences of a given corpus for instance subjects direct or indirect objects of verbs and builds a network of words and phrases in which each phrase is linked to its syntactic heads and expansions The network is then used as a material for the construction of semantic classes on a distributional basis i e the grouping of words and phrases appearing in similar syntactic contexts for an accurate description of the distributional analysis module see Bourigault 2002 We will focus here on the extraction of lexico syntactic dependencies with an emphasis on PP attachment as they are the starting point in the whole process and will give an overview of the general principles underlying the analysis Syntex s major specificity is to rely on endogenous techniques Bourigault 1994 which allow the parser to acquire for every new corpus analysed the subcategorization information necessary to resolve syntactic attachment ambiguity This strategy is based on in depth studies of various domain corpora highlighting idiosyncratic uses of lexico syntactic structures compared with their general use and from one domain to another Fabre a
17. how that this approach does not take into account some particular features such as syntactic constraints which restrict the cooccurrence of arguments Moreover a general syntactic description using basic semantic features such as human abstract place etc is obviously unsatisfactory for the description of LSPs whatever the use of the description is The classes of arguments that take the different syntactic positions must be described extensively hence the necessity of automatic term extraction However using regular expressions we tried to extract lists of potential arguments for verbs Below is an example of extraction for the verb to run that shows that there is still noise in the result run w w w w onfunderjat w 0 30 run fdisk or cfdisk on it for you Of the two cfdisk is runs to control everything on a machine AND one is run per run the following program on the client include lt stdio h gt run the serial interface at a FIXED speed whilst allowing run your NIS slaves on a Linux box Or perhaps your The manual description made use of comparison with general language The Herald Tribune Le Monde in order to check the degree of specialisation of some verbs using thus the contextual criterion to decide on the term status of verbs Although newspapers are not completely representative of the language in general they are general enough to give good hints on the degree of specificity of a term 3 2
18. lysis We first point to a few arguments in favour of verb analysis and then give a brief overview of the automatic tool we used Finally we show through Prepositional Phrase PP attachment how endogenous techniques are well adapted to our verb study 4 Corpus based automatic analysis 4 1 A few arguments in favour of verb analysis As mentioned in Section 1 both verb analysis and description are crucial and terminology acquisition tools are therefore expected to yield verb related results though most tools do not go as far as verb output Let us insist on three at least reasons accounting for a verb oriented analysis Reason From a terminological point of view verbs may be terms just as nouns do following Bourigault and Jacquemin 2000 who postulate a verb terminology Indeed verbs play a major role in specialised texts and are likely to be terms on the basis that they can be i morphologically related to a noun or noun phrase being itself a term such as the French and English examples injecter un virus injection d un virus to access the system an access to the system ii specialised verbs usually simple verbs i e verbs whose use is restricted to a given domain and refer to a specific concept such as the French verbs transduire or transfecter in the domain of gene therapy or the English CS verbs to telnet to bufferize iii verbs exhibiting a deviant use in the terminological system in comparison with their e
19. nd Bourigault 2001 Basili et al 1997 Basili et al 1999 In this context using general linguistic knowledge tends to prove quite inefficient and irrelevant Consequently Syntex does not use any a priori linguistic resources Let us illustrate the endogenous strategy on PP attachment the very first procedure in delimitating phrases B indicates a wrong analysis invalid term 4 There is a French version of Syntex as well as an English version S Before Syntex is used the corpus is morphosyntactically tagged each word in the corpus is assigned a lemma and grammatical tag Example in the French noun phrase plan de faille plan is the head and faille the extension English Example Verb Noun Preposition Ambiguous case to run programs in virtual terminals gt potential governors for the preposition in program ie in run In order to solve this ambiguous case in other words find the preposition s governor our tool relies on unambiguous cases i e cases containing only one governor such as Unambiguous cases Dosemu has to be run in another terminal compile and run in double precision mode why not run in a Linux box your NIS slaves Syntex relies on those unambiguous cases to compute productivity measures used to perform the right attachment run in terminal mode box corpus based occurrences run in productivity 3 gt to run different programs in virtual terminals We now illustrate
20. r control by booting the French chef and his staff French examples extracted from the general corpus of Le Monde show immediate differences in the use of lancer as a translation of to boot et l hymne fraternel que lance a ce dernier J r me Garcin MCI se lance dans la bataille des autoroutes de Martine Aubry lance le d bat sur le partage du temps de travail The last verb we will exemplify for the corpus based manual description here is to dump The Robert amp Collins Super Senior English French dictionary gives the following examples and French translations which are not in the corpus dump Comput data file etc vider to dump to the printer transf rer sur l imprimante To dump shows transitive locative constructions such as No dumps N on N with the following argument classes 1 a fast computer can dump 32k of data on you qu un ordinateur rapide pourra vous inonder de 32ko de donn es No dumps N to onto N2 with the following argument classes http www cogsci princeton edu wn 10 Guillet A et Lecl re Ch 1992 La structure des phrases simples en fran ais tome II constructions transitives locatives Gen ve Droz No Nhum N data content memory e N disk file 2 dumps its memory image to disk in executable format crit l image de sa memoire sur le disque sous format binaire 3 you just dump the contents of one disk onto the other en copiant directemen
21. reposition Occurrences against as from to into to compile things against this library to compile as ELF to cross compile from with in in support in Linux to Dos the steps to compile into the kernel the driver was compiled with support for out of debugging enabled to compile in your own personal values to compile in support to use the program selection you need to compile in support for your CDROM drive it compiles right out of the box on Linux configure as for in in support for configuring your machine as an NCP server the card is configured for shared on to under with memory operation allow the card to be configured in software do not configure in support for the 82C710 devices to be configured on a Linux machine the card is not configured to one of the addresses configure CDROM drive under Linux you have configured dosemu with a command like dump on into onto to back to you can dump 32k of data on you without stopping it will dump everything into a ftape 2 when you just dump the contents of one disk onto the other dump the image to the disk dumping its memory image back to disk mount as for from into on name of the directory to mount as root to mount a CDROM for read write a through under with CDROM is mounted from Linux to mount Novell volumes into your Linux filesystems mounting the CDROM on bootup mount the empty files through the loopback devices you dos partition is assumed
22. rived from nouns with no other information than part of speech Bilingual glossaries are likely to give translations of verbs but with very little syntactic and semantic information on how to use them in a sentence The need for describing verbs as terms has been experienced in various applications K bler and Foucou to appear show that French learners of CS English face major comprehension and production problems that are very often related to specialised verbs Building corpus based teaching applications of CS English requires a full description of the specialised verbs of the domain K bler 2002 shows the need for verb description in specialised translation especially when machine translation is used by non programming translators This need raises the issue of sorting out verb terms from general verbs in specialised texts In the lexicographic area L Homme 1993 1998 tried to forge definition criteria for verbs as terms in the French general CS domain The first criterion consists in considering that if the arguments of the verb are terms there is a high probability that the verb is a term too This criterion is however based on the a priori characterisation of a term Pearson 1998 suggests that the context is the only way of making the difference between a term and a word Fr rot 2001 has shown that arguments belonging to the general lexicon could indicate the presence of a verb term by collocating with the verb revealing a partic
23. t le contenu d un disque sur un autre The different French translations account for two different uses depending on the preposition on or in to A query on the Herald Tribune corpus shows that the specialised uses are quite different from the general ones i e no occurrence of the preposition to for defying his demands to dump her boyfriend and cut her long hair overseas investors will dump Japanese stocks The storm which dumped 23 centimeters 9 inches of snow Saturday in Tokyo The same applies to French General uses of crire and copier show significant differences as far as structures and argument classes are concerned Ecrire sur la mort d un ami est p rilleux R alis avec de gros moyens ce film copie Alien sans vergogne alors elles nous copient sur les sp cialit s In this section the corpus based manual description highlighted idiosyncratic uses of verbs in our corpus Even though we used aligned concordances to carry out the analysis the procedure as it is not fully automated was time consuming and quite hard working However this methodology proved useful to highlight the uses that are specific to CS and do not belong to general language Therefore we investigated the possibility of using a corpus based automatic tool both for French and English that would yield verb related results and above all relies on the corpus as much as possible Section 4 is thus dedicated the a corpus based automatic ana
24. this procedure with a French example French example gt introduire du mat riel g n tique dans les cellules ce qui permet de les introduire dans une cible a introduit dans une cellule eucaryote de l 4DN du mat riel g n tique a t introduit dans l organisme introduire dans cible cellule organisme corpus based occurrences introduire dans productivity 3 gt introduire du mat riel g n tique dans les cellules 4 3 First experiment on the HOWTO corpus 4 3 1 A few remarks on pre processing As mentioned earlier Section 2 1 the HOWTO corpus is characterised by a vast number of features such as URLs e mail addresses code names command lines or scripts among others that make the task of pre processing difficult by pre processing we mean sentence and word segmentation as well as morphosyntactic tagging For instance the high number of enumerations in the form of listing adds to the difficulty of sentence segmentation which becomes even more complex with the naturally occurring dimension referring to the lack of homogeneity in punctuation typography due in part to different people writing the user guide be it in English or for the French translations As far as the morphosyntactic tagging is concerned the tagset used covers part of the corpus specificities the NomMail and NomUrl tags are well suited to analyse phenomena such as URLs or e mail addresses examples NomMail timbo moshpit air n
25. tion de connaissances a partir de textes Th se de l Ecole des Hautes Etudes en Sciences Sociales Paris Bourigault D 2002 Upery un outil d analyse distributionnelle tendue pour la construction d ontologies a partir de corpus Actes de la conf rence TALN Nancy 75 84 Bourigault D Jacquemin C 2000 Construction de ressources terminologiques Jn J M Pierrel Ingenierie des langues Paris Herm s Sciences Publications Chap 9 p 215 233 Bourigault D Fabre C 2000 Approche linguistique pour l analyse syntaxique de corpus Cahiers de grammaire Vol 25 pp 131 151 Bourigault D Slodzian M 1999 Pour une terminologie textuelle Terminologies nouvelles 19 29 32 Chodkiewicz C Bourigault D Humbley J 2002 Making a workable glossary out of a specialised corpus Term extraction and expert knowledge in Altenberg B amp Granger S eds Lexis in contrast corpus based approaches John Benjamins Publishing Company Amsterdam Philadephia pp 249 267 Condamines A 1995 Terminology new trends new perspectives Terminology 2 2 219 238 Fabre C Bourigault D 2001 Linguistic clues for corpus based acquisition of lexical dependencies Actes de Corpus Linguistics Conference Lancaster pp 176 184 Fr rot C 2001 Caract risation du verbe en terminologie Application au domaine de la th rapie g nique en canc rologie M moire de DEA Universit Paris 7 K bler N 2002 Teaching Commercial MT to translators Bridging the Gap between
26. to be mounted under Linux the root filesystem is mounted with write access The automatic analysis of the French translations for boot compile configure dump mount run showed very frequent verb preposition associations be they long distance or adjacent such as for boot lancer d marrer a partir de dans sur or run faire tourner ex cuter dans sous depuis Our endogeous procedures proved efficient to resolve the PP attachment ambiguities Syntactico lexical redundancy in the corpus was sufficient for the parser to correctly attach the preposition to the verb Finally it should be pointed out that so far no distinction is made in the parser between arguments and adjuncts of verbs Whatever the status of PPs not as clear cut as often claimed they are attached to the verb This choice is based on the assumption that non argumental relations between verbs and PPs highly contribute to word semantic neighbouring hence to word semantic class More generally speaking corpus based tools may highlight and bring new insight to linguistic phenomena as is the case here for the argument adjunct distinction that an intuition based manual description strongly influenced by categorical models of grammar would not show 5 Conclusion and future work 18 We exclude wrong analyses due to tagging errors This first experiment has shown the necessity of using corpus based manual description as an incentive for automatic term extra
27. ular behaviour which is different from its general use The second criterion defined by L Homme considers verbs that are related to other lexical units that have already been identified as terms The issue of the a priori term determination remains unsolved Furthermore verbs and nouns terms that are morphologically related are not always terminologically related The analysis undertaken in this paper takes those criteria into account but goes further in considering the syntactic differences the verb terms exhibit compared with their general use The syntactic criterion has revealed to be most important as general language intermingles with LSPs in specialised texts Most verbs that can be found in the general language have specific syntactic behaviours in LSPs and are subject to very specifically defined semantic restrictions Fr rot 2001 We will use the verb term expression to refer to verbs that can be considered as terms Consequently both verb analysis and description are crucial and terminology acquisition tools are therefore expected to yield verb related results In designing Syntex a corpus based parser used to generate lexical resources from specialised corpora Bourigault and Fabre 2000 have taken it into consideration and have extended automatic extraction to verbs and verb phrases Indeed a verb oriented analysis can improve terminology extraction as it helps to better identify syntactic dependencies in the sentences of a corpus as
28. ull HOWTO corpus which means ca 500 000 words in each language the Internet RFCs ca 8 5 million words were also used to double check some uncertain uses To make sure a verb structure was deviant i e specific to the subject area compared with the general language we also used French and English newspapers one year of The Herald Tribune and of Le Monde 2 1 Characterisation of the parallel corpus in Computer Science The HOWTOs are highly specialised texts written by CS experts who are not always English native speakers The documents are aimed at CS experts and therefore do not address a wide audience The communication context can be that of an expert to expert communication and share the following parameters It is assumed that author and reader share a common language and that when certain words or phrases are used each understands what is meant Writer and reader or speaker and hearer are assumed to have the same level of expertise This expert to expert communication context is likely to be the one with the highest density of terms Pearson 1998 The HOWTOs show therefore a high percentage of terms and present features that are specific to very specialised CS texts such as command names code lines URLs e mail addresses etc Below is an example of the type of highly specialised sentences that can be found EN Java API with c tree Plus ISAM functionality gives Java functionality through native metho
29. well as it enhances the distributional analysis i e the grouping of words and phrases appearing in similar syntactic contexts used for the construction of semantic classes 2 Framework of the experiment Corpus linguistics has now proven to yield reliable and sometimes surprising linguistic information However the need for automating linguistic information extraction has increased as globalization raises the issue of multilingual document processing Term extraction will thus become a key issue for the language industry helping to build multilingual databases or ontologies for the semantic Web applications Term extraction not only deals with well written texts revised and corrected by language professionals It will have to deal more and more with naturally occurring texts showing ill formed language and various genres For this reason we decided to choose a corpus that was very specialised and provided a good example of naturally occurring texts the Linux HOWTOs which are the user manual of the Linux operating system Those texts have not been written by language professionals and are highly specialised They have been written in English and translated into many languages among which French Aware of the needs for bilingual but also multilingual terminologies we worked on the English and French versions The sample we used consisted of 200 000 words in either language To check for uses in case of doubt we also used the f
30. xpected use in the lexical system In this context deviance refers to the unpredictable verb argument structure both in terms of syntactic and semantic behaviour Fr rot 2001 Let us illustrate that point with the following corpus based examples construire des souris recruter des cellules the daemon listens to all the messages Reason 2 A verb oriented analysis improves automatic term extraction as it helps to better identify the constituents frontiers of sentences in a corpus therefore increasing noun extraction accuracy Let us look at the following examples The corpus based examples in section 4 are taken from the French English HOWTO corpus and French corpora in the domain of geomorphology and gene therapy 2 we postulated deviance as the linguistic characteristic of terms in relation to words The deviance was described as being of several kinds 1 Unsually high frequency of compound verbs 2 Coinage of new words 3 Unusual syntactic behaviour new or forbidden constructions 4 Unusual semantic behaviour appareance of new meanings which show themselves by unsual combinations Condamines 1995 a to boot a Linux kernel on a CD ROM gt 3 Linux kernel on a CD ROM gt to boot on a CD ROM Linux kernel b to give the compiler hints about how to optimize gt compiler hints gt to give hints compiler c enrober de calcite des mat riaux gt calcite des mat riaux
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