Linked Resources towards Enhancing the Conceptual Description of General Lexis Verbs Using Syntactic Information (2022)

Abstract: 214–224

## related work significant efforts have been invested in aligning and in some cases expanding the mapping between semantic and syntactic resources in the past two decades and this interest has been growing in recent years. a number of proposals have brought together the advantages of conceptual and lexical information encoded in resources such as wordnet, framenet, verbnet and others. such works include the mapping of wordnet, framenet and verbnet by @xcite , the elaboration of wordframenet foot_0 by @xcite and mapnet foot_1 by @xcite , the implementation of other framenet-to-wordnet mappings, such as the one by @xcite . more enhanced linked resources include semlink foot_2 @xcite , which unifies wordnet, framenet and verbnet with propbank, and its follow-up semlink+ that brings in a mapping to ontonotes @xcite . more recently, the synsemclass lexicon foot_3 has marked a distinguishable effort towards combining the rich semantic description in the vallex dictionary family with conceptual and syntactic information from external semantic resources in order to create a multilingual contextually-based verb lexicon. the aim of the lexicon is to provide a resource of classes of verbs that compares their semantic roles as well as their syntactic properties @xcite . in addition, each entry is linked to framenet, wordnet, verbnet, ontonotes and propbank, as well as the czech vallex. verbatlas foot_4 , proposed @xcite , is a hand-crafted lexical semantic resource which represents synsets as clusters with prototypical argument structures presented as frames, to a large extent inspired by verbnet roles and semantic restrictions. one of the main concerns related to resource alignment has been the limited coverage. hence, another line in the research on semantic resource linking has been the expansion of inter-resource coverage. @xcite have proposed a method for enriching fn frame-to-wn synset alignment based on exploring the structural features of the two resources. in particular, they study candidate frames evoked by literals (individual members of synsets) related to a target literal through certain semantic relations, such as synonymy, hypernymy, antonymy, and assign weights to them according to the adopted methodology. di @xcite adopt a strategy of clustering wordnet synsets according to semantic similarity and associating them with frames that describe the predicate-argument structure and selectional restrictions of each cluster. while these frames are inspired by verbnet, the clustering algorithm achieves much better coverage of wordnet synsets as compared with wordnet-verbnet mappings relying on the lexical correspondence of the units in the two resources. another proposal for expansion of the mapping between framenet and wordnet proposed by @xcite and further refined in @xcite makes use of the relational structure of the two resources. the method involves the mapping of framenet frames to wordnet synsets on the basis of the inheritance of conceptual features in hypernym trees, i.e., by assigning frames from hypernyms to hyponyms where possible and implementing a number of validation procedures based on the structural properties of the two resources, primarily the relations encoded in them. another venue of research has been to map relevant information representing fragments of meaning associated with lexical units across resources, especially essential components of the semantic and the syntactic description such as semantic roles or their counterparts in the respective resources (e.g. frame elements, argument positions, valency slots). alignments at the verb arguments' level have been carried out as part of the semlink project and its more recent version semlink 2.0. @xcite . the alignments described there include propbank to verbnet mappings (propbank roleset -verbnet senses, pb arguments -verbnet semantic roles) as well as verbnet to framenet mappings (verbnet senses -framenet frames, verbnet semantic roles -framenet frame elements). another similar task, which makes use of the linking of various semantic resources (framenet, wordnet, verbnet, ontonotes and propbank), has been implemented in the development of the synsemclass lexicon @xcite : the more general synsemclass valency slots have been mapped to relevant framenet frame elements. in this paper we build upon previous efforts in aligning and expanding the coverage of semantic resources by mapping semantic and syntactic elements of the description of their basic units, in particular: framenet frame elements and verbnet semantic roles (along with the selectional restrictions defined for them in the two resources) and the syntactic patterns associated with the verbs in the respective framenet frame and verbnet class. instead of using it directly, we employ the mapping provided in semlink and semlink+ @xcite as a reference set to compare to our own mapping for a couple of reasons: some classes are only marginally corresponding to a given frame so the alignment needs to be considered more carefully; as framenet's and verbnet's descriptions do not always correspond straightforwardly, the semantic roles and frame elements may have one-to-many or many-to-many mappings or actually not be counterparts of each other despite a seeming coincidence or similarity in the names or proceedings of clib 2022 definitions. the availability of a mapping to compare our independent results will make the analysis of debatable cases more reliable. in addition, we map the syntactic patterns capturing the expression of the semantic roles for the verb classes in verbnet and the valency patterns for the verbs in a given frame in framenet. this procedure is aimed at providing an additional syntactic level of comparison between the two resources that may inform studies and applications both for english and for other languages. the syntactic correspondences are also applicable in semantic role -frame element mapping or mapping validation procedures, especially in cases where the semantic roles and the frame elements are not successfully mapped but have equivalent syntactic expression. we consider two main research questions: to what extent is syntactic information language independent and can it be transferred from english to less-resourced languages such as bulgarian? the contributions of the paper include: ## resources below we describe in brief the used resources and how they are integrated with each other. ## dataset compilation the three resources have been mapped automatically using existing mappings or newly designed procedures in such a way that wordnet synsets are assigned corresponding verb classes from verbnet and frames from framenet where possible. the previously implemented mappings have been supplemented and partially validated. in particular, the following have been employed: a mapping of the verbnet 3.4 verb classes to wordnet synsets, as well as two types of mappings of the frames in framenet and the synsets in wordnet: indirectly via semlink and directly through the system described by @xcite . in addition, in order to increase the inter-resource coverage between wn synsets and fn frames, we have used an expanded synset-to-framenet frame mapping described in detail in @xcite . the focus of the study are general lexis verbs in wordnet. we are aiming at compiling a lexical resource of verbs of high frequency and wide usage supplied with conceptual description and syntactic frames. the main source of the description is the information from the framenet frame and verbnet class aligned to the wordnet synset. the resource will serve as a model and can be further expanded to cover other verbs. ## discussion of results the task of aligning framenet and verbnet poses a number of challenges. this task is approached by employing (i) the semantic alignment of the fine-grained framenet frame elements to the more generalised verbnet semantic roles using straightforward correspondences and the frame element hierarchy discussed in 3.3; (ii) the syntactic mapping -correspondences in terms of syntactic categories, prepositions, subordinating conjunctions, types of clauses, etc.between frame elements and verbnet roles with similar semantics and place in the conceptual description of particular verbs. ## conclusions and future work the research presented in this paper aims at providing a reliable alignment between: (a) framenet frame elements and verbnet semantic roles on the basis of mapped fn frame -vn verb class pairs assigned to a number of wordnet synsets; (b) framenet lexical units' syntactic patterns and verbnet syntactic frames. these combined allows for expanding the conceptual description of verbs with information about their syntactic realisation. further, the data offer extensive opportunities to investigate to what extent the conceptual and the syntactic information can be transferred between languages, especially languages from one language family. these observations can play a crucial role in expanding semantic and syntactic description of bulgarian verbs and thus, boost the development of new nlp applications.