National audienceIn this paper we argue that the account of the notion of complex type based on copredication tests is problematic,because copredication is possible,albeit less frequent, also with expressions which exhibit polysemy due to coercion.We show through a distributional and lexico-syntactic pattern-based corpus analysis that the variability of copredication contexts is the key to distinguish complex types nouns from nouns subject to coercion

Jezek, Elisabetta

Vieu, Laure

In this paper we argue that the account of the notion of complex type based on copredication tests is problematic,because copredication is possible,albeit less frequent, also with expressions which exhibit polysemy due to coercion.We show through a distributional and lexico-syntactic pattern-based corpus analysis that the variability of copredication contexts is the key to distinguish complex types nouns from nouns subject to coercion

Open Archive Toulouse Archive Ouverte

     Open Archive TOULOUSE Archive Ouverte (OATAO)  OATAO is an open access repository that collects the work of Toulouse researchers and makes it freely available over the web where possible.  This is an author-deposited version published in : http://oatao.univ-toulouse.fr/ Eprints ID : 13287   To cite this version : Jezek, Elisabetta and Vieu, Laure Distributional analysis of copredication : towards distinguishing systematic polysemy from coercion. (2014) In: First Italian Conference on Computational Linguistics (CLiC-it), 9 December 2014 - 10 December 2014 (Pisa, Italy). Any correspondance concerning this service should be sent to the repository administrator: staff-oatao@listes-diff.inp-toulouse.fr Distributional analysis of copredication:Towards distinguishing systematic polysemy from coercionElisabetta JezekUniversita` di Paviajezek@unipv.itLaure VieuIRIT-CNRS - Universite´ Toulouse IIIvieu@irit.frAbstractEnglish In this paper we argue that theaccount of the notion of complex typebased on copredication tests is problem-atic, because copredication is possible,albeit less frequent, also with expres-sions which exhibit polysemy due to co-ercion. We show through a distributionaland lexico-syntactic pattern-based corpusanalysis that the variability of copredica-tion contexts is the key to distinguish com-plex types nouns from nouns subject to co-ercion.Italiano In questo contributo sosteniamoche il test di copredicazione utilizzato inletteratura per motivare l’esistenza di tipicomplessi e` problematico, in quanto la co-predicazione e` possibile, seppur con mi-nor frequenza, anche con espressioni cheesibiscono un comportamento polisemicoa seguito di coercion. Attraverso unaanalisi distribuzionale che utilizza patternlessico-sintattici mostriamo come la vari-abilita` dei contesti di copredicazione e` lachiave per distinguere nomi associati atipi complessi da nomi soggetti a coercion.1 IntroductionCopredication can be defined as a “grammaticalconstruction in which two predicates jointly applyto the same argument” (Asher 2011, 11). We focushere on copredications in which the two predicatesselect for incompatible types. An example is (1):(1) Lunch was delicious but took forever.where one predicate (‘take forever’) selects for theevent sense of the argument lunch while the other(‘delicious’) selects for the food sense.Polysemous expressions entering such copred-ication contexts are generally assumed to have acomplex type (Pustejovsky 1995), that is, to lexi-cally refer to entities “made up” of two (or more)components of a single type; it is thus assumedfor example that lunch is of the complex typeevent • food.1 Copredication as a defining cri-terion for linguistic expressions referring to com-plex types is, however, problematic, because co-predication is possible, albeit less frequent, alsowith expressions which exhibit polysemy becauseof coercion, as in the case of the noun sandwich insuch contexts as (2):(2) Sam grabbed and finished the sandwich inone minute.where the predicate grab selects for the simpletype the noun sandwich is associated with (food),whereas finish coerces it to an event. The claimthat the event sense exhibited by sandwich is co-erced is supported by the low variability of eventcontexts in which sandwich appears (as opposed tolunch); see for example “during lunch” (780 hitsfor the Italian equivalent in our reference corpus,cf. section 3) vs. “*during the sandwich” (0 hits).Our goal is therefore twofold: evaluate whetherat the empirical level it is possible to distin-guish, among nouns appearing in copredicationcontexts, between complex types and simple (orcomplex) types subject to coercion effects; andpropose a method to extract complex type nounsfrom corpora, combining distributional and lexico-syntactic pattern-based analyses. Our working hy-pothesis is that lexicalized complex types appearin copredication patterns more systematically, andso that high variability of pair of predicates in co-predication contexts is evidence of complex typenouns, while low variability points to simple (orcomplex) type nouns subject to coercion effects.In the sections that follow, we will first raise thequestions what counts as a copredication and what1Dot/complex types have received different terminologiesin the literature, particularly nouns with facets (Cruse 1995)and dual aspect nouns (Asher 2011).copredication really tell us about the underlyingsemantics of the nouns that support it. Then, wewill introduce the experiments we conducted sofar to verify our hypothesis. Finally, we will drawsome conclusions and point at the experiments wehave planned as future work.2 Copredication2.1 What counts as a copredication?In the literature, what exactly counts as a copred-ication is not clear. Typically, copredication hasbeen restricted to classic coordinative construc-tions as in (3), where the adjective voluminoso‘bulky’ selects for the physical sense of book,while impegnativo ‘demanding’ selects for the in-formational one.(3) E` un libro voluminoso e impegnativo.‘It is a bulky and demanding book’.Research has shown, however, that copredica-tion patterns based on coordination do not fre-quently mix different aspects but tend to predicateon a single aspect, as in (4), where both adjectivesselect for the same event aspect of costruzione‘construction’ (Jezek and Melloni 2011):(4) La costruzione fu lenta e paziente.‘The construction was slow and patient’.Moreover, it has been claimed that construc-tions different from coordinative (or disjunctive)ones can be copredicative; for example, copredi-cations with anaphoric pronouns (5)a, and struc-tures where one of the predicates is located in asubordinative clause, as in (5)b and (5)c.(5) a. He paid the bill and threw it away.(Asher 2011, 63).b. La construction, qui a commence´ hier,sera tre`s jolie (Jacquey 2001, 155).‘The building, which started yesterday,will be very nice’.c. Una volta completata, la traduzione sipuo` caricare in una sezione apposita delsito (Jezek and Melloni 2011, 27).‘Once completed, the translation may beuploaded in a special section of the site’.These copredication patterns may be disputablefrom both a structural and semantic point of viewbecause they involve pronouns and coreference,and one could argue that pronominalization leavesroom for phenomena such as bridging and asso-ciative anaphora.In our work we focus on what we argue is a lessdisputable copredication pattern, namely [V [DetN Adj]]. This pattern is instantiated in contextssuch as the following, where for example the pred-icate bruciavano selects for the physical aspect ofbook, whereas controversi selects for the informa-tional one:(6) ... bruciavano i libri controversi.‘... they burned the controversial books’.2.2 What does copredication really tell us?As referenced above, it has also been notedthat copredication may actually involve coercion(Asher and Pustejovsky 2006; corpus evidence inPustejovsky and Jezek 2008). Consider:(7) Aprire il vino rosso con 30 minuti di anticipo.‘Open the red wine 30 minutes in advance’.In (7), vino ‘wine’ appears to denote both drinkand container in the same context, due to the twopredicates rosso ‘red’ and aprire ‘open’. Despitethe apparent polysemy, the noun vino is generallyassumed to be lexically associated with a simpletype (drink), and to license a sense extension tocontainer in specific contexts only, as a coercioneffect induced by the semantic requirements of theselecting predicate.We claim that a single occurrence of a relevantcopredication context is not enough to identify acomplex type, and we conjecture that a variety ofcopredication contexts appearing with enough reg-ularity might constitute evidence. Indeed, one canobserve that vino ‘wine’ displays a limited vari-ability, since it cannot be coerced into a containertype by any predicate that would felicitously applyto bottiglia ‘bottle’, as shown by (8):(8) *Ho rotto il vino rosso.‘I broke the red wine’.3 The experimentWe conducted a corpus-based study to assessthe possibility to empirically distinguish betweencomplex types and simple (or complex) types sub-ject to coercion effects through the analysis of co-predication contexts. The concrete goal of the ex-periment was, for a given complex type, to extracta list of candidate nouns that do appear in somecopredication context, and compute the variabil-ity of copredication contexts to order these nouns.The hypothesis is that nouns shall be ordered frommost likely being of the complex type at staketo most likely being of some other type but sub-ject to coercion. We exploited the SketchEngine(Kilgarriff et al. 2014) tagged Italian corpus It-TenTen10 (2,5 Gigawords) and its tools. Thecomplex type chosen for this first experiment wasinformation object • physical object of which‘book’ is taken to be the prototype in the literature,and as detailed above, the copredication patternsused are of the form [V [Det N Adj]].3.1 Predicate extractionThe copredication contexts of interest are thosebased on a transitive verb and an adjective thateach select for a different type. The first step wastherefore to pick four lists of predicates: transi-tive verbs selecting for information object (Info)or physical object (Phys) as object complementsand adjectives that modify nouns of either type.The starting point was a list of 10 seed nouns2considered as good examples of the complex type.We extracted from the corpus predicates apply-ing to these seed nouns, that are frequent andshared enough: on the most frequent 200 verbs(V) and adjectives (A) in the collocational pro-files (WordSketches) of each of these seed nouns,we performed 2-by-2 intersections and then union,which yielded 427 V and 388 A. We manuallydoubly classified them into Phys and Info, avoid-ing predicates (too) polysemic, generic, or subjectto metaphorical uses. We thus gathered 65 VPhys,53 VInfo, 18 APhys and 127 AInfo.3.2 Candidate extractionUsing a manually selected subset of 6-14 fre-quent predicates of each category, a series of con-cordance built on the copredication pattern withall context pairs 〈VPhys, AInfo〉 and 〈VInfo,APhys〉 produced nouns occurring in these con-texts. We then manually annotated 600+ randomlytaken hits, checking for actual copredication withboth aspects, thus extracting 97 different nouns.The 5 seed nouns not present among these 97 wereadded, obtaining 102 nouns, as candidates for thecomplex type Info • Phys. For the rest of theexperiment, since the relevant copredications arerather sparse, we focussed on the 54 nouns withfrequency above 200,000, and selected 28 (52%)ones, aiming at covering most of the various typesappearing among these and including 7 seed nouns(marked * in the table).2 articolo, diario, documento, etichetta, fumetto, giornale,lettera, libro, racconto, romanzo (‘article’, ‘diary’, ‘docu-ment’, ‘label’, ‘comic’, ‘newspaper’, ‘letter’, ‘book’, ‘shortnovel’, ‘novel’)3.3 Computing the copredication contextvariabilityFor all 28 nouns we extracted all occurrences ofthe [V [Det N Adj]] pattern, N fixed. The hits ofeach lexico-syntactic pattern are grouped by pairs〈V, A〉 that we here call “copredication contexts”for this noun. We then extract the relevant contexts〈VPhys, AInfo〉 and 〈VInfo, APhys〉 combiningselected predicates in our four lists. The ratio ofrelevant contexts among all contexts is an indica-tor of the variability of Info • Phys copredicationcontexts for each noun, and this variability a signof the conventionalisation of the lemma ability tojointly denote both Phys and Info referents.The results, ordered from more variable to lessvariable, appear on Table 1, where Hits is the to-tal number of hits of the lexico-syntactic pattern,Cop. hits are those hits with a relevant 〈VPhys,AInfo〉 or 〈VInfo, APhys〉 context, Contexts isthe total number of 〈V, A〉 contexts, and Cop.cont. are the relevant ones. Ratios are in %.Note that the hit ratio would yield a differentorder than the context ratio, since a single relevantcontext may have a large incidence. Indeed, withcontext ratio, the 7 seed nouns are ranked amongthe 10 first, while with the hit ratio, they would ap-pear among the 14 first, and include at the very topinformazione and indicazione, two nouns unlikelyprototypes for the Info • Phys complex type.4 DiscussionThe copredication contexts extracted are sparse,and the ratio figures ordering the nouns are low (allbelow 3%). This might be due to the phenomenonof copredication across types being sparse, butobviously also because the 4 lists of predicatesare by no means exhaustive. On the basis of amanual annotation of 200 (0,8%) hits on libro,the recall is estimated at 6%. A very high re-call could not be reached without including pol-ysemic or very generic predicates, thus loweringprecision. Precision has been estimated for libro:118 (86%) extracted copredication hits are indeedrelevant cases. However, in the lower rows, pre-cision drops: 9 (60%) for volume and even 0 forfenomeno, which means that if we had other meansto screen the results, the ratio range would widenbetween top and bottom rows.The method allows to distinguish four groupsof lemmas (statistically significant partition, butfiner-grained partitions could be drawn). At theLemma Freq. Hits Cop. hits Hit ratio Contexts Cop. cont. Cont. ratiolettera (letter)* 549552 13386 414 3.1 5513 130 2.4giornale (newspaper)* 276139 6757 37 0.55 968 20 2.1documento (document)* 547415 25615 313 1.2 11404 182 1.6informazione (information) 1092596 68201 2635 3.9 18459 242 1.3racconto (short novel)* 243777 7533 111 1.5 4418 56 1.3capitolo (chapter) 218115 4982 60 1.2 2731 32 1.2articolo (article)* 2458766 12885 104 0.81 6588 72 1.1libro (book)* 968401 23958 137 0.57 10856 107 0.99pagina (page) 716615 15850 111 0.70 8357 82 0.98romanzo (novel)* 213778 7644 47 0.61 3844 35 0.91testo (text) 528482 21080 108 0.51 9067 81 0.89immagine (image) 641384 32097 256 0.80 19146 162 0.85indicazione (indication) 279063 20831 651 3.1 6536 54 0.83relazione (report) 744398 36274 467 1.3 15693 101 0.64storia (story) 1505947 57074 235 0.41 21292 129 0.61programma (program) 978951 39140 340 0.87 18029 103 0.57parola (speech) 1087778 44619 139 0.31 16292 87 0.53gioco (game) 637619 16815 60 0.36 8859 43 0.49proposta (proposal) 716391 28007 149 0.53 12254 58 0.47serie (series) 668564 12824 40 0.31 6872 31 0.45dichiarazione (statement) 339720 13601 33 0.24 5817 25 0.43fonte (source) 354620 20912 35 0.17 7692 33 0.43riferimento (reference) 691282 18193 57 0.31 6705 27 0.40ricerca (research) 1378351 25002 103 0.41 12228 46 0.38carattere (character) 378986 45632 131 0.29 20504 70 0.34volume (volume) 307808 6732 15 0.22 4445 15 0.34pezzo (piece) 286093 13190 27 0.20 7201 23 0.32prodotto (product) 837772 48285 72 0.15 20391 54 0.26fenomeno (phenomenon) 342726 26876 20 0.074 11872 13 0.11Table 1: Relevant copredication variability for 28 candidate Info • Phys nouns with high frequencytop, are those that arguably are prototypical exam-ples of the complex type Info •Phys. Next comesa group of nouns with still classical examples ofthis dot-type, especially libro, as well as nouns ofthe simple type Info such as informazione. Sinceinformation objects generically depend on theirphysical realizations, coercion is readily available.What these data tell us is that the pure Info senseof libro (as in il libro di Dante e` stato tradottoin tante lingue ‘Dante’s book has been translatedin many languages’) or immagine might prevailover their complex type sense. The next groupgathers many nouns of a different complex type,Info • Event, such as speech act nouns, some ofwhich, like relazione, do also have a lexicalizedsense of document, while others, like indicazioneand dichiarazione, are rather subject to coercion.The last group exhibits occasional coercion con-texts, with the exception of volume which doeshave a standard Info • Phys sense but much lessfrequent than its spatial or sound quality sense.We can therefore conclude that an experimentalmethod to separate nouns of complex types fromnouns subject to coercion appears possible. Theproposed method constitutes the first attempt atsemi-automatically extracting from corpus com-plex type nouns, something remaining elusive upto now. In addition, we learned that letter shouldbe preferred over book as prototype of the com-plex type Info•Phys. In fact, this complex type isnot the most straightforward since the dependencebetween the components of a dot object is not one-to-one. The case of Event • Food with lunch asprototype, in which there is such a tight symmetricdependence and no competition with separate sim-ple senses, might prove easier to deal with. Thiswill be tackled in a next experiment.The predicate selection is a critical phase in themethod proposed. It is difficult if not impossibleto avoid polysemy and metaphorical uses, espe-cially since the relevant copredications are sparseand we cannot rely only on highly specialized un-frequent predicates. In future work, we plan to ex-periment with fully automatic selection, exploitingdistributional semantics methods. Dimension re-duction through non-negative matrix factorizationyields a possible interpretation of the dimensionsin terms of “topics”, which is confirmed by ex-periments (Van de Cruys et al. 2011). Buildingon this, we shall check whether “topics” for predi-cates correspond to selectional restrictions suitableto build our copredication patterns.AcknowledgmentsThanks to Philippe Muller for help with program-ming issues and to the participants of the work-shop on dot objects in May 2014 in Toulouse forfeedback on early results of this work. We also ac-knowledge Tommaso Caselli and two anonymousreviewers for their useful comments.BibliographyN. Asher. 2011. Lexical Meaning in Context: AWeb of Words. Cambridge: Cambridge UniversityPress.N. Asher and J. Pustejovsky. 2006. A type com-position logic for generative lexicon. Journal ofCognitive Science, 6, 1–38.D.A. Cruse. 1995. Polysemy and related phenom-ena from a cognitive linguistic viewpoint. In P.Saint-Dizier and E. Viegas Computational LexicalSemantics, CUP, 33–49.E. Jacquey. 2001. Ambiguite´s Lexicales et Traite-ment Automatique des Langues: Mode´lisationde la Polyse´mie Logique et Application auxde´verbaux d’action ambigus en Franc¸ais. Ph.D.Dissertation, Universite´ de Nancy 2.E. Jezek, and C. Melloni. 2011. Nominals, Pol-ysemy and Co-predication. Journal of CognitiveScience, 12, 1–31.A. Kilgarriff, V. Baisa, J. Busˇta, M. Jakubı´cˇek, V.Kova´rˇ, J. Michelfeit, P. Rychly´, and V. Suchomel.2014. The sketch engine: ten years on. Lexicog-raphy, 1–30. http://www.sketchengine.co.uk/J. Pustejovsky. 1995. The Generative Lexicon.Cambridge, MA: MIT Press.J. Pustejovsky, J. and E. Jezek. 2008. Semanticcoercion in language: Beyond distributional anal-ysis. Distributional Models of the Lexicon in Lin-guistics and Cognitive Science. Special Issue onItalian Journal of Linguistics, 20(1), 175–208.T. Van de Cruys, T. Poibeau, and A. Korhonen.2011. Latent vector weighting for word meaningin context. Proceedings of the Conference on Em-pirical Methods in Natural Language Processing.

Distributional analysis of copredication: towards distinguishing systematic polysemy from coercion

National audienceIn this paper we argue that the account of the notion of complex type based on copredication tests is problematic,because copredication is possible,albeit less frequent, also with expressions which exhibit polysemy due to coercion.We show through a distributional and lexico-syntactic pattern-based corpus analysis that the variability of copredication contexts is the key to distinguish complex types nouns from nouns subject to coercion.In questo contributo sosteniamo che il test di copredicazione utilizzato in letteratura per motivare l’esistenza di tipicomplessi `e problematico, in quanto la copredicazione `e possibile, seppur con minor frequenza, anche con espressioni che esibiscono un comportamento polisemico a seguito di coercion. Attraverso una analisi distribuzionale che utilizza pattern lessico-sintattici mostriamo come la variabilit`a dei contesti di copredicazione `e la chiave per distinguere nomi associati a tipi complessi da nomi soggetti a coercion

Scientific Publications of the University of Toulouse II Le Mirail

In this paper we argue that the account of the notion of complex type based on copredication tests is problematic, because copredication is possible, albeit less frequent, also with expressions which exhibit polysemy due to coercion. We show through a distributional and lexico-syntactic pattern-based corpus analysis that the variability of copredication contexts is the key to distinguish complex types nouns from nouns subject to coercion

JEZEK, ELISABETTA

Vieu, L.

Archivio Istituzionale della Ricerca - Università degli Studi di Pavia

Distributional Analysis of Copredication: Towards Distinguishing Systematic Polysemy from Coercion

https://hal.archives-ouvertes.fr/hal-01154483

Distributional analysis of copredication: towards distinguishing systematic polysemy from coercion

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Scientific Publications of the University of Toulouse II Le Mirail

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