Computational Grammar Research Articles

Construction grammar and procedural semantics for human-interpretable grounded language processing

Abstract Grounded language processing is a crucial component in many artificial intelligence systems, as it allows agents to communicate about their physical surroundings. State-of-the-art approaches typically employ deep learning techniques that perform end-to-end mappings between natural language expressions and representations grounded in the environment. Although these techniques achieve high levels of accuracy, they are often criticized for their lack of interpretability and their reliance on large amounts of training data. As an alternative, we propose a fully interpretable, data-efficient architecture for grounded language processing. The architecture is based on two main components. The first component comprises an inventory of human-interpretable concepts learned through task-based communicative interactions. These concepts connect the sensorimotor experiences of an agent to meaningful symbols that can be used for reasoning operations. The second component is a computational construction grammar that maps between natural language expressions and procedural semantic representations. These representations are grounded through their integration with the learned concepts. We validate the architecture using a variation on the CLEVR benchmark, achieving an accuracy of 96 %. Our experiments demonstrate that the integration of a computational construction grammar with an inventory of interpretable grounded concepts can effectively achieve human-interpretable grounded language processing in the CLEVR environment.

Restricted Computations and Parameters in Type-Theory of Acyclic Recursion

The paper extends the formal language and the reduction calculus of Moschovakis type-theory of recursion, by adding a restrictor operator on terms with predicative restrictions. Terms with restrictions over memory variables formalise inductive algorithms with generalised, restricted parameters. The extended type-theory of restricted recursion (TTRR) provides computations for algorithmic semantics of mathematical expressions and definite descriptors, in formal and natural languages. The reduction calculi of TTRR provides a mathematical foundation of the work of compilers for reducing recursive programs to iterative ones. The type-theory of acyclic recursion (TTAR) has a special importance to syntax-semantics interfaces in computational grammars.

Word-level prosodic and metrical influences on Hawaiian glottal stop realization.

Previous research on the phonetic realization of Hawaiian glottal stops has shown that it can be produced several ways, including with creaky voice, full closure, or modal voice. This study investigates whether the realization is conditioned by word-level prosodic or metrical factors, which would be consistent with research demonstrating that segmental distribution and phonetic realization can be sensitive to word-internal structure. At the same time, it has also been shown that prosodic prominence, such as syllable stress, can affect phonetic realization. Data come from the 1970s-80s radio program Ka Leo Hawai'i. Using Parker Jones' (Parker Jones, Oiwi. 2010. A computational phonology and morphology of Hawaiian. University of Oxford DPhil. thesis) computational prosodic grammar, words were parsed and glottal stops were automatically coded for word position, syllable stress, and prosodic word position. The frequency of the word containing the glottal stop was also calculated. Results show that full glottal closures are more likely at the beginning of a prosodic word, especially in word-medial position. Glottal stops with full closure in lexical word initial position are more likely in lower frequency words. The findings for Hawaiian glottal stop suggest that prosodic prominence does not condition a stronger realization, but rather, the role of the prosodic word is similar to other languages exhibiting phonetic cues to word-level prosodic structure.

A Framework for Malay Computational Grammar Formalism based-on Enhanced Pola Grammar

In the era of IR4.0, Natural Language Processing (NLP) is one of the major focuses because text is stored digitally to code the information. Natural language understanding requires a computational grammar for syntax and semantics of the language in question for this information to be manipulated digitally. Many languages around the world have their own computational grammars for processing syntax and semantics. However, when it comes to the Malay language, the researchers have yet to come across a substantial computational grammar that can process Malay syntax and semantics based on a computational theoretical framework that can be applied in systems such as e-commerce. Hence, we intend to propose a formalism framework based on enhanced Pola Grammar with syntactic and semantic features. The objectives of this proposed framework are to create a linguistic computational formalism for the Malay language based on theoretical linguistic; implement templates for Malay words to handle syntax and semantic features in accordance with the enhanced Pola Grammar; and create a Malay Language Parser Algorithm that can be used for digital applications. To accomplish the objectives, the proposed framework will recursively formalise the computational Malay grammar and lexicon using a combination of solid theoretical linguistic foundations such as Dependency Grammar. A Malay parsing algorithm will be developed for the proposed model until the formalised grammar is deemed reliable. The findings of this indigenous Malay parser will help to advance Malay language applications in the digital economy.

Evaluating the Bantu parametric grammar in grammatical framework using Swahili grammar

Monologue grammar development for under-resourced languages is very slow and laborious (involves creating rules to generate the computational grammar to enable analysis and synthesis of the language(s) in question). However, the need for computational grammar continues to soar in this technology-driven economy for information synthesis and analysis. This paper aims to set up an experiment in the grammatical framework (GF), to evaluate the efficiency and effectiveness of the Bantu parameterized grammar to bootstrap a new grammar for Swahili. The goal is to investigate how this approach of bootstrapping grammar in a multilingual environment is effective and efficient in reducing the development effort. The bootstrapping approach uses the GF morphology-driven approach to develop portable and unique segments of Swahili grammar. The bootstrapped Swahili grammar resulted in a shareability of 100%, 71.11%, 68.75%, and 91.41% at category linearization, paradigms, parameters and syntax rules respectively. The portability was at 15.55%, 18.57%, and 8.59% at paradigms, parameters and syntax rules, respectively. Finally, this paper contributes in: first, provides an approach that leads to an effective and efficient method for developing and bootstrapping computational grammar for the under-resourced Bantu languages. Secondly, the research provided a Swahili grammar.

Computational modeling of a generative grammar for clitic order in River Plate Spanish

Abstract The order of clitics (CLs) in Romance languages has been studied in depth by many scholars since Perlmutter’s first approach. This author points out that person and case features impose a filter that results in the following pattern in Spanish: Se- II- I- III dat - III acc . This pattern has been revisited because it is not restrictive enough: it gives rise to impossible sequences. In this context, the goal of this work is to define a pattern of morphosyntactic features for River Plate Spanish clitics, and an ordering pattern, with the purpose of developing a computational model for an automatic analysis of this phenomenon. This kind of analysis is justified because the algorithm output shows the degree of success of the descriptive proposal. To this end, we use NooJ, a linguistic development environment that has diverse tools. The computational modeling involves two stages: (i) the creation of an electronic dictionary and (ii) the creation of a computational grammar. The algorithm developed can generate all correct sentences conformed by Nominative Pronoun + CL + CL + Verb, Non-Finite Verb-CL-CL and Imperative Verb-CL-CL, and it can recognize these kinds of expressions in written text assigning the correct semantic labels. With these results, we conclude that our descriptive proposal is adequate for the analysis of sequences of clitics in River Plate Spanish.

Grammatical error detection using HPSG grammars: Diagnosing common Mandarin Chinese grammatical errors

Computational Grammars can be adapted to detect ungrammatical sentences, effectively transforming them into error detection (or correction) systems. In this paper we provide a theoretical account of how to adapt implemented HPSG grammars for grammatical error detection. We discuss how a single ungrammatical input can be reconstructed in multiple ways and, in turn, be used to provide specific, high-quality feedback to language learners. We then move on to exemplify this with a few of the most common error classes made by learners of Mandarin Chinese. We conclude with some notes concerning the adaptation and implementation of the methods described here in ZHONG, an open-source HPSG grammar for Mandarin Chinese.

Competing prosodic influences on VOT length in Hawaiian

Previous research on voice onset time shows that VOT in unaspirated stops is at best only weakly affected by prosodic strengthening (Hodgson, 2021; Simonet et al., 2014). VOT duration is analyzed in Hawaiian, which has only /p k/, in conjunction with a prosodic analysis, to determine its stop type, and investigate whether prosodic boundaries condition VOT length. Data comprise speech from seven speakers interviewed on the radio program Ka Leo Hawai‘i in the 1970–80s (Kettig, 2021). Using the computational prosodic grammar in Parker Jones (2010), stops were coded for whether they occurred in lexical word-initial/medial position, in a stressed/unstressed syllable, and in prosodic word-initial/medial position. The results indicate that the average duration of /p/ is 24ms and /k/ is 41ms, the latter being on the higher end of unaspirated stop ranges (Cho and Ladefoged, 1999). VOT is significantly longer before stressed word-medial syllables, but shorter before stressed word-initial syllables. For word-medial stressed syllables, VOT is also significantly longer when the syllable is in prosodic-word initial position. VOT length may have separate functions in Hawaiian unaspirated stops: strengthen a lexical word boundary especially before an unstressed syllable via shortening, but lengthen word-medially to demarcate a prosodic word boundary.

The FCG Editor: An innovative environment for engineering computational construction grammars.

Since its inception in the mid-eighties, the field of construction grammar has been steadily growing and constructionist approaches to language have by now become a mainstream paradigm for linguistic research. While the construction grammar community has traditionally focused on theoretical, experimental and corpus-based research, the importance of computational methodologies is now rapidly increasing. This movement has led to the establishment of a number of exploratory computational construction grammar formalisms, which facilitate the implementation of construction grammars, as well as their use for language processing purposes. Yet, implementing large grammars using these formalisms still remains a challenging task, partly due to a lack of powerful and user-friendly tools for computational construction grammar engineering. In order to overcome this obstacle, this paper introduces the FCG Editor, a dedicated and innovative integrated development environment for the Fluid Construction Grammar formalism. Offering a straightforward installation and a user-friendly, interactive interface, the FCG Editor is an accessible, yet powerful tool for construction grammarians who wish to operationalise their construction grammar insights and analyses in order to computationally verify them, corroborate them with corpus data, or integrate them in language technology applications.

Grammar Engineering for the Ekegusii Language in Grammatical Framework

The knowledge-driven economy uses technology, thereby increasing the demand for language tools and resources to acquire and distribute the knowledge. Such tools and resources are scarce for the under resourced, spoken Bantu languages. This paper develops a computational grammar for the Ekegusii language in the Grammatical Framework (GF) to bridge the gap. The grammar development uses a bottom-up and modular-driven approach. A machine translation experiment was set up to evaluate the grammar resulting in BLEU and PER of 55.95% and 19.49%, respectively. This work contributes by providing computational grammar for an under-resourced language, thus providing a platform for analysis and synthesis, plus a machine translation within the GF ecosystem.

Grammar Engineering for the Ekegusii Language in Grammatical Framework

The knowledge-driven economy uses technology, thereby increasing the demand for language tools and resources to acquire and distribute the knowledge. Such tools and resources are scarce for the under resourced, spoken Bantu languages. This paper develops a computational grammar for the Ekegusii language in the Grammatical Framework (GF) to bridge the gap. The grammar development uses a bottom-up and modular-driven approach. A machine translation experiment was set up to evaluate the grammar resulting in BLEU and PER of 55.95% and 19.49%, respectively. This work contributes by providing computational grammar for an under-resourced language, thus providing a platform for analysis and synthesis, plus a machine translation within the GF ecosystem.

A computational construction grammar approach to semantic frame extraction

Abstract This paper introduces a novel methodology for extracting semantic frames from text corpora. Building on recent advances in computational construction grammar, the method captures expert knowledge of how semantic frames can be expressed in the form of conventionalised form-meaning pairings, called constructions. By combining these constructions in a semantic parsing process, the frame-semantic structure of a sentence is retrieved through the intermediary of its morpho-syntactic structure. The main advantage of this approach is that state-of-the-art results are achieved, without the need for annotated training data. We demonstrate the method in a case study where causation frames are extracted from English newspaper articles, and compare it to a commonly used approach based on Conditional Random Fields (CRFs). The computational construction grammar approach yields a word-level F1 score of 78.5%, outperforming the CRF approach by 4.5 percentage points.

A writing assistant en route to a full computational grammar for Sepedi

A detailed user study and observations by lecturers indicate that the correct compilation of sentences in the eight verbal moods as well as for a number of similar grammatically complicated constructions in Sepedi poses a challenge in any text production situation. Feedback from target users indicated that there is a need for a computational writing assistant for the compilation and verification of correct constructions. To address this need, an extended computational sentence builder for verbal moods, adjectives and possessive constructions in Sepedi was designed and built to assist in text production and to serve as a model for other African languages. This article introduces a prototype of such an extended computational sentence builder for verbal moods, adjectives and possessive constructions in Sepedi. The emphasis throughout is on the grammatical complexity of Sepedi and how the Sepedi Helper can assist users to produce correct sentences. In contrast to typical traditional grammars of Sepedi, the tool also provides the required cognitive information through basic clickable help screens. The Sepedi Helper is a dynamic lightweight tool aimed at combining user knowledge with a text production tool, i.e. user-involved, step-by-step production of Sepedi phrases. The emphasis in the design is on simplicity.

French de and en as expressions of the genitive case: a unified analysis within LFG and computational implementation in XLE

ABSTRACT The French clitic pro-form en represents a wide range of heterogeneous constituents: de-PP complements and adjuncts, partitive objects, and prepositionless objects of cardinals. The main goal of this paper is to formalize this relationship computationally in terms of genitive case. This is apparently the first non-transformational counterpart to Kayne (1975)’s unified analysis, which derives en from a deep structure with de by means of syntactic transformations. Transformational grammars are problematic from the parsing perspective. In order to test our analysis automatically on a large amount of data, we implemented it in a computational grammar of French in the Lexical-Functional Grammar (LFG) formalism using the XLE system. This non-transformational framework is particularly fit for expressing systematic relationships between heterogeneous structures and has successfully been used for the implementation of natural language grammars since the 1980s. We tested the implementation on 320 grammatical sentences and on an equal number of ungrammatical examples. It analyzed all grammatical examples and blocked almost 95% of the ungrammatical ones, showing a high empirical adequacy of the grammar.

Designing Learning Outcomes in Design Higher Education Curricula

AbstractNew and flexible educational paradigms, based on creative, innovative and open‐minded competences, are required in the development of curricula in design, working as an essential skill toolkit for future designers, particularly in higher education. This study aims to explore how learning outcomes, usually expressed by the knowledge, skills, abilities, attitudes and competences expected to be achieved by students as a result of an educational experience, are defined and formulated in design study programmes in Portugal. The investigation relies on the linguistic analysis of a corpus composed of a collection of learning outcomes extracted from the Portuguese undergraduate and post‐graduate study programmes in design. The analysis was performed through the application of natural language tools and resources to that corpus. Specifically, we used computational lexicons and grammars to gather information on word frequency, lexical density, syntactic distribution and the morphology used in texts. Additional discourse dimensions, such as the length of sentences, the frequency of specific linguistic patterns, and the presence of subjective items, like evaluative adjectives, were also considered. Results suggest that Portuguese design and art higher education institutions are committed to follow the learning outcomes recommendations, trying to identify measurable ‘design’ skills. Moreover, the results show that, despite of being confined to 1,000 characters, learning outcomes are expressed differently, both in terms of lexicon and grammar, depending on the study cycles, fostering the idea that skills and competences required become more complex as the level of qualification increases.

Global Syntactic Variation in Seven Languages: Toward a Computational Dialectology.

The goal of this paper is to provide a complete representation of regional linguistic variation on a global scale. To this end, the paper focuses on removing three constraints that have previously limited work within dialectology/dialectometry. First, rather than assuming a fixed and incomplete set of variants, we use Computational Construction Grammar to provide a replicable and falsifiable set of syntactic features. Second, rather than assuming a specific area of interest, we use global language mapping based on web-crawled and social media datasets to determine the selection of national varieties. Third, rather than looking at a single language in isolation, we model seven major languages together using the same methods: Arabic, English, French, German, Portuguese, Russian, and Spanish. Results show that models for each language are able to robustly predict the region-of-origin of held-out samples better using Construction Grammars than using simpler syntactic features. These global-scale experiments are used to argue that new methods in computational sociolinguistics are able to provide more generalized models of regional variation that are essential for understanding language variation and change at scale.

Computational construction grammar for visual question answering

Abstract In order to be able to answer a natural language question, a computational system needs three main capabilities. First, the system needs to be able to analyze the question into a structured query, revealing its component parts and how these are combined. Second, it needs to have access to relevant knowledge sources, such as databases, texts or images. Third, it needs to be able to execute the query on these knowledge sources. This paper focuses on the first capability, presenting a novel approach to semantically parsing questions expressed in natural language. The method makes use of a computational construction grammar model for mapping questions onto their executable semantic representations. We demonstrate and evaluate the methodology on the CLEVR visual question answering benchmark task. Our system achieves a 100% accuracy, effectively solving the language understanding part of the benchmark task. Additionally, we demonstrate how this solution can be embedded in a full visual question answering system, in which a question is answered by executing its semantic representation on an image. The main advantages of the approach include (i) its transparent and interpretable properties, (ii) its extensibility, and (iii) the fact that the method does not rely on any annotated training data.

Towards Kikamba Computational Grammar

The under-resourced Kikamba language has few language technology tools since the more efficient and popular data driven approaches for developing them suffer from data sparseness due to lack of digitized corpora. To address this challenge, we have developed a computational grammar for the Kikamba language within the multilingual Grammatical Framework (GF) toolkit. GF uses the Interlingua rule-based translation approach. To develop the grammar, we used the morphology driven strategy. Therefore, we first developed regular expressions for morphology inflection and thereafter developed the syntax rules. Evaluation of the grammar was done using one hundred sentences in both English and Kikamba languages. The results were an encouraging four n-gram BLEU score of 83.05% and the Position independent error rate (PER) of 10.96%. Finally, we have made a contribution to the language technology resources for Kikamba including multilingual machine translation, a morphology analyzer, a computational grammar which provides a platform for development of multilingual applications and the ability to generate a variety of bilingual corpora for Kikamba for all languages currently defined in GF, making it easier to experiment with data driven approaches.

HPSG analysis and computational implementation of Indonesian passives

This study aims to analyze and develop a detailed model of syntax and semantics of passive sentences in standard Indonesian in the framework of Head-Driven Phrase Structure Grammar (HPSG) (Pollard & Sag, 1994; Sag et al., 2003) and Minimal Recursion Semantics (MRS) (Copestake et al., 2005), explicit enough to be interpreted by a computer, focusing on implementation rather than theory. There are two main types of passive in Indonesian, following Sneddon et al. (2010, pp. 256-260) and Alwi et al. (2014, pp. 352-356), called ‘passive type 1’ (P1) and ‘passive type 2’ (P2). Both types were analyzed and implemented in the Indonesian Resource Grammar (INDRA), a computational grammar for Indonesian (Moeljadi et al., 2015).

Exploring the Creative Potential of Computational Construction Grammar

Abstract Computational construction grammar aims to provide concrete processing models that operationalise construction grammar accounts of the different aspects of language. This paper discusses the computational mechanisms that allow construction grammar models to exhibit, to a certain extent, the creativity and inventiveness that is observed in human language use. It addresses two main types of language-related creativity. The first type concerns the ‘free combination of constructions,’ which gives rise to the open-endedness of language. The second type concerns the ‘appropriate violation of usual constraints’ that permits language users to go beyond what is possible when adhering to the usual constraints of the language, and be truly creative by relaxing these constraints and by introducing novel constructions. All mechanisms and examples discussed in this paper are fully operationalised and implemented in Fluid Construction Grammar.