An agent-based model of the emergence and evolution of a language system for boolean coordination

This paper presents an agent-based model of the emergence and evolution of a language system for Boolean coordination. The model assumes the agents have cognitive capacities for invention, adoption, abstraction, repair and adaptation, a common lexicon for basic concepts, and the ability to construct complex concepts using recursive combinations of basic concepts and logical operations such as negation, conjunction or disjunction. It also supposes the agents initially have neither a lexicon for logical operations nor the ability to express logical combinations of basic concepts through language. The results of the experiments we have performed show that a language system for Boolean coordination emerges as a result of a process of self-organisation of the agents' linguistic interactions when these agents adapt their preferences for vocabulary, syntactic categories and word order to those they observe are used more often by other agents. Such a language system allows the unambiguous communication of higher-order logic terms representing logical combinations of basic properties with non-trivial recursive structure, and it can be reliably transmitted across generations according to the results of our experiments. Furthermore, the conceptual and linguistic systems, and simplification and repair operations of the agent-based model proposed are more general than those defined in previous works, because they not only allow the simulation of the emergence and evolution of a language system for the Boolean coordination of basic properties, but also for the Boolean coordination of higher-order logic terms of any Boolean type which can represent the meaning of nouns, sentences, verbs, adjectives, adverbs, prepositions, prepositional phrases and subexpressions not traditionally analysed as forming constituents, using linguistic devices such as syntactic categories, word order and function words.Peer ReviewedPostprint (author's final draft

Syntactic and Semantic Underspecification in the Verb Phrase.

This thesis is concerned with verbs and the relation between verbs and their complements. Syntactic evidence is presented which shows that the distinction between arguments and adjuncts reflects the optionality of adjuncts, but that adjuncts, once introduced, behave as arguments of the verb. An analysis is proposed which reflects this observation by assuming that verbal subcategorization is underspecified, so that optional constituents can be introduced into the verb phrase. The analysis is developed within a formal model of utterance interpretation. Labelled Deductive Systems for Natural Language (LDSNL), proposed in Kempson, Meyer-Viol & Gabbay (1999), which models the structural aspect of utterance interpretation as a dynamic process of tree growth during which lexical information is combined into more complex structures which provide vehicles for interpretation, propositional forms. The contribution of this thesis from the perspective of utterance interpretation is that it explores the notion of structural underspecification with respect to predicate-argument structure. After providing a formalization of underspecified verbal subcategorization, the thesis explores the consequences this analysis of verbs and verb phrases has for the process of tree growth, and how underspecified verbs are interpreted. The main argument developed is that verbs syntactically encode the possibilty for pragmatic enrichment; verbs address mental concepts only indirectly, so that the establishment of their eventual meaning, and, therefore, their eventual arity is mediated by the cognitive process of concept formation. Additional support for this view is provided by an analysis of applied verbs in Swahili which, from the perspective adopted here, can be seen to encode an explicit instruction for concept strengthening, an instruction to the hearer to derive additional inferential effects. The analysis presented in this thesis thus supports the view that natural language interpretation is a process in which structural properties and inferential activity are thoroughly intertwined

Extraction and Coordination in Phrase Structure Grammar and Categorial Grammar

A large proportion of computationally-oriented theories of grammar operate within the confines of monostratality (i.e. there is only one level of syntactic analysis), compositionality (i.e. the meaning of an expression is determined by the meanings of its syntactic parts, plus their manner of combination), and adjacency (i.e. the only operation on terminal strings is concatenation). This thesis looks at two major approaches falling within these bounds: that based on phrase structure grammar (e.g. Gazdar), and that based on categorial grammar (e.g. Steedman). The theories are examined with reference to extraction and coordination constructions; crucially a range of 'compound' extraction and coordination phenomena are brought to bear. It is argued that the early phrase structure grammar metarules can characterise operations generating compound phenomena, but in so doing require a categorial-like category system. It is also argued that while categorial grammar contains an adequate category apparatus, Steedman's primitives such as composition do not extend to cover the full range of data. A theory is therefore presented integrating the approaches of Gazdar and Steedman. The central issue as regards processing is derivational equivalence: the grammars under consideration typically generate many semantically equivalent derivations of an expression. This problem is addressed by showing how to axiomatise derivational equivalence, and a parser is presented which employs the axiomatisation to avoid following equivalent paths

Morphotactics in Affix Ordering: Typology and Theory

This dissertation discusses the empirical distribution and systematicity of morphotactic rules on the relative order of verbal affixes. In the literature, the exact role of morphology and its interaction with other factors affecting affix order is still under debate. More specifically, syntactic (Baker 1985, 1988) and semantic approaches (Muysken 1986, Rice 2000, Stiebels 2003) to affix order assume that some underlying grammatical structure, the syntactic derivation or the semantic composition, is mapped transparently onto the surface, such that the relative order of affixes on the surface matches the underlying order of the elements. However, phenomena like nontransitive affix order or templatic morphology suggest that morphological rules may overwrite the surface order provided by syntax or semantics. In this dissertation, I examine exactly these phenomena to investigate the empirical scope of these morphological rules. I demonstrate that there are crosslinguistically stable, systematic rules of morphology, which are in direct competition with rules of syntactic or semantic transparency. Concretely, I conclude that there is a morphological rule that requires the realization of causatives in proximity of the verb root. The role and systematicity of morphotactics in affix order is highly relevant for linguistic theory: if seemingly arbitrary rules influence affix order without any restriction, it is impossible to build restrictive theories. Thus, uncovering the crosslinguistic patterns of morphological rules help to build empirically adequate, restrictive theories about affix order. Furthermore, I demonstrate that the interaction of affix order with phonology suggests a cyclic model of the morpho-phonology interface. More specifically, I assume that phonology has temporarily limited access to morphological structure, thus deriving well-attested cases of phonologically conditioned affix order. To model the competition between rules of morphology on the one hand and rules of syntax and semantics on the other hand, I suggest a concrete mechanism that translates the underlying semantic composition into a restricted set of constraints. Consequently, the simultaneous interaction between these constraints implementing transparency requirements and morphotactic constraints derives the variety of transparency patterns found in combinations of valency markers

The polysemy of selected motion verbs in Sesotho

Thesis (MA)--Stellenbosch University, 2003.ENGLISH ABSTRACT: The subject of this study is the polysemy of the motion verbs in Sesotho. Motion verbs can be classified as verbs of process or transition. This study examines the semantic and the syntactic properties of motion verbs in Sesotho. These motion verbs include verbs denoting process e.g. -ya, -tla, -tsamaya, -baleha, -nyoloha and -theoha as shown in the sentences below: a. Monna 0 ya toropong. 'The man goes to town' b. Bashanyana ba tsamaya thoteng. 'The boys walk in the veld' c. Bana ba tla hae. 'The children come home' d. Bashemane ba balehile mophatong. 'The initiates run away from the initiation school' e. Tshwene e theoha sefateng. 'The baboon descends from the tree' f. Banna ba nyoloha thaba. 'Men ascend the mountain' The study demonstrates that motion verbs in Sesotho are semantically divided into verbs denoting 'to go' e.g. -ya, verbs denoting 'to walk', e.g. -tsamaya, verbs denoting 'to run away', e.g. -baleha, verbs denoting to ascend, e.g. -nyoloha, verbs denoting to descend, e.g. -theoha. The study further demonstrates that these verbs are canonically intransitive. The study provides evidence that motion verbs are characterized by specific selection restrictions and event structures. The study further demonstrates that motion verbs are used with different subjects denoting (groups of) people, animals, abstract nouns, mass nouns, nouns denoting food, intoxicating and nonintoxicating liquids, natural phenomena, artifacts, natural object, possession/property, humans and animals. Lastly the lexical conceptual paradigm, providing the different word senses of each verb, is examined.AFRIKAANSE OPSOMMING: Die onderwerp van hierdie studie is die polisemie van bewegingswerkwoorde m Sesotho. Bewegingswerkwoorde kan gekarakteriseer word as werkwoorde van proses (aktiwiteit) of transisie. Hierdie studie ondersoek die semantiese en sintaktiese eienskappe van bewegingswerkwoorde in Sesotho. Hierdie werkwoorde sluit in werkwoorde wat 'n proses (aktiwiteit) aandui, byvoorbeeld -~, -tla, -tsamaya, -baleha, -nyoloha en -theoha, soos geïllustreer in die volgende sinne: a. Monna 0 ya toropong. 'Die man gaan dorp toe' b. Bashanyana ba tsamaya thoteng. 'Die seuns loop in die veld' c. Bana ba tla hae. 'Die kinders gaan huis toe' d. Bashemane ba balehile mophatong. 'Die inisiante hardloop weg van die inisiasieskool' e. Tshwene e theoha sefateng. 'Die bobbejaan daal afuit die boom' f. Banna ba nyoloha thaba. 'Die mans bestyg die berg' Die studie demonstreer dat bewegingswerkwoorde in Sesotho semanties geklassifiseer kan word in werkwoorde wat beteken 'om te gaan', bv. -~, werkwoorde wat beteken 'om te loop', bv. -tsamaya, werkwoorde wat beteken 'om (weg) te hardloop', bv. -baleha, werkwoorde wat beteken 'om te bestyg', bv. -nyoloha, en werkwoorde wat beteken 'om afte daal', bv. -theoha. Die studie demonstreer verder dat bewegingswerkwoorde in Sesotho tiperend onoorganklik is. Daar word aangetoon dat hierdie werkwoorde gekenmerk word deur spesifieke seleksiebeperkings en gebeure-strukture ('event structures'). Die studie toon op uitgebreide wyse aan dat bewegingswerkwoorde in Sesotho met onderwerpe gebruik kan word wat verskillende semantiese tipes verteenwoordig, en wat verskillende kenmerke het, insluitende onderwerpe wat menslike individue, groepe mense of diere aandui, abstrakte naamwoorde, massanaamwoorde, voedsel, vloeistowwe, natuurlike verskynsels, artifakte, natuurlike voorwerpe, of be sittings

The compilation of corpus-based Setswana dictionaries

The aim of this thesis is to describe how corpus-based Setswana dictionaries should be compiled. The challenge to the modern Setswana lexicographer is to compile very practical descriptive and user-friendly dictionaries. A detailed evaluation of existing Setswana dictionaries will be performed in terms of the macrostructural and microstructural aspects: Coverage of frequently used words. Effective use of dictionary space. Use of standard dictionary conventions. Choice, ordering and composition of translation equivalent paradigms. The focus will be on material collection and corpus building. Informants will be used to compile an oral corpus of 100,000 tokens. All ethical requirements such as informed consent requirements (See Appendix 1) will be honoured. Since the text corpus is an organic corpus, thus not a designed corpus aimed at balance and representativeness, the oral corpus will be constructed in the same way i.e. only basic selection criteria: Mother tongue speakers of Setswana. Adults (to be on a par with authors of the written sources in the text corpus). Age: ranging from 20-60 years. Male and female. Critical analysis of all currently available Setswana dictionaries will be done with special reference to the dictionaries of Brown (1987) (SESD), Snyman, et al. (1990), Matumo (1993).(MSED), Kgasa (1976) (THAND) and Kgasa and Tsonope (1995).(THAN) In all these cases the strategy would be in terms of the theoretical criteria and best practices in terms of a broad theoretical survey of core aspects of dictionary compilation. Finally, the study will be concluded with an analysis of corpus integrity and stability of Setswana corpora based on the model introduced by Prinsloo and De Schryver (2001a).Thesis (DLitt)--University of Pretoria, 2009.African LanguagesUnrestricte

An investigation into deviant morphology : issues in the implementation of a deep grammar for Indonesian

This thesis investigates deviant morphology in Indonesian for the implementation of a deep grammar. In particular we focus on the implementation of the verbal suffix -kan. This suffix has been described as having many functions, which alter the kinds of arguments and the number of arguments the verb takes (Dardjowidjojo 1971; Chung 1976; Arka 1993; Vamarasi 1999; Kroeger 2007; Son and Cole 2008). Deep grammars or precision grammars (Butt et al. 1999a; Butt et al. 2003; Bender et al. 2011) have been shown to be useful for natural language processing (NLP) tasks, such as machine translation and generation (Oepen et al. 2004; Cahill and Riester 2009; Graham 2011), and information extraction (MacKinlay et al. 2012), demonstrating the need for linguistically rich information to aid NLP tasks. Although these linguistically-motivated grammars are invaluable resources to the NLP community, the biggest drawback is the time required for the manual creation and curation of the lexicon. Our work aims to expedite this process by applying methods to assign syntactic information to kan-affixed verbs automatically. The method we employ exploits the hypothesis that semantic similarity is tightly connected with syntactic behaviour (Levin 1993). Our endeavour in automatically acquiring verbal information for an Indonesian deep grammar poses a number of lingustic challenges. First of all Indonesian verbs exhibit voice marking that is characteristic of the subgrouping of its language family. In order to be able to characterise verbal behaviour in Indonesian, we first need to devise a detailed analysis of voice for implementation. Another challenge we face is the claim that all open class words in Indonesian, at least as it is spoken in some varieties (Gil 1994; Gil 2010), cannot linguistically be analysed as being distinct from each other. That is, there is no distiction between nouns, verbs or adjectives in Indonesian, and all word from the open class categories should be analysed uniformly. This poses difficulties in implementing a grammar in a linguistically motivated way, as well discovering syntactic behaviour of verbs, if verbs cannot be distinguished from nouns. As part of our investigation we conduct experiments to verify the need to employ word class categories, and we find that indeed these are linguistically motivated labels in Indonesian. Through our investigation into deviant morphological behaviour, we gain a better characterisation of the morphosyntactic effects of -kan, and we discover that, although Indonesian has been labelled as a language with no open word class distinctions, word classes can be established as being linguistically-motivated