Establishing Morpho-semantic Relations in F ars N et (a focus on derived nouns) (2016)

Abstract: This paper aims at a morpho-semantic analysis of 2461 Persian derived nouns, documented in FarsNet addressing computational codification via formulating specific morpho-semantic relations between classes of derived nouns and their bases. Considering the ultimate aim of the study, FarsNet derived nouns included 12 most productive suffixes have been analysed and as a consequence 45 morpho-semantic patterns were distinguished leading to creation of 17 morpho-semantic relations. The approach includes a close examination of beginners, grammatical category and part of speech shifts of bases undergoing the derivation process. In this research the morpho-semantic relations are considered at the word level and not at the synset level which will represent a cross-lingual validity, even if the morphological aspect of the relation is not the same in the studied languages. The resulting morpho-semantic formulations notably increase linguistic and operative competence and performance of FarsNet while is considered an achievement in Persian descriptive morphology and its codification.

## introduction a comprehensive and detailed description of the relevant linguistic levels is a prerequisite for achieving progress in natural language processing (nlp). wordnets are very popular lexical ontologies, relying on morphological, semantic and morpho-semantic descriptions and formulations. farsnet which is a persian wordnet has been established in 2009 by nlp research lab of shahid beheshti university. it goes closely in lines and principles of princeton wordnet, eurowordnet and balkanet @xcite . the latest version of farsnet (2.0) contains 22180 nouns (including 2756 derived nouns), 5691 verbs, 6560 adjectives and 2014 adverbs. besides semantic relations (synonymy, hypernymy, hyponymy, meronymy and antonymy) and morphological relations (derivation), some additional conceptual relations such as domain and related to, have been devised in farsnet. at present (2015), it consists of more than 36000 entries, organized in almost 2000 synsets. the present study which is aimed at formulating morphosemantic relations of farsnet's derived nouns provides the wordnet with the basic required information for automation of the relations. according to @xcite , a morphosemantic process decomposes derived, compound and complex words into their base and associates such process to their semantic interpretation. through morpho-semantic analysis derived and compound words are analysed morphologically and relations between base and derivational form are interpreted semantically @xcite . @xcite consider "morphosemantics" as the best expression describing studies which deal with links between form and meaning at the word level. derivation and compounding are the two main word formation processes. persian derivational morphology consists of an affixal system in which the number of suffixes is more than prefixes. persian derivational morphological processes include suffixation, prefixation, only a single case of circumfixation and no infixation (davari and arvin 2015). affixation patterns in this language are generally regular however in some cases there are few exceptions @xcite . according to @xcite persian derivational processes are relying on almost 56 suffixes. the aim of the present study is to neatly explore, formulate and classify the morpho-semantic patterns of derived nouns by analysing the relevant data in farsnet. it is worth noting that the present article originates from a wider scope research by @xcite , in which all farsnet derived nouns (2756) were analysed in order to establish morpho-semantic relations between derived nouns and their bases. the derived nouns under study included 26 different suffixes. in this study the derivatives of 12 most productive noun marker suffixes (2461) have been focused. this study enriches farsnet while improves morphosemantic codification of persian. after a brief introduction to farsnet word entries in general and noun entries in particular, the process of morpho-semantic pattern formulation will be elaborated for the selected suffixes. ## farsnet word entries entries include phonological transcription, part of speech, synonyms and their classifications in to a synset, word meaning and an example. a beginner will be selected for each lexeme. according to @xcite a beginner is a primitive semantic component of any word in its hierarchically structured semantic field. beginners could be used in the recognition of domains synsets. different syntactic types can be related to each other in farsnet; mapping each entry to its corresponding concept in princeton wordnet 3.0 is also possible @xcite . using this information is essential in establishing morpho-semantic relations. the synsets which do not fall into any of the above categories will be tagged by the label nothing. the semantic relations are also established among the synsets with the same pos. synsets with different pos will be tagged by labels such as "related to". there are 3 choices for mapping a synset to the correspondent one in princeton wordnet 3.0: equivalence mapping, near-equivalence mapping and no-mapping. finally, the morphological relations among senses, such as derivational relations are marked. besides specifying a noun type (such as common, proper, countable, uncountable, pronoun, number or infinitive), a classification on the basis of some more general semantic features (such as belonging to human, animal, location or time) is provided. ## data analysis for the purpose of this study the noun corpus of farsnet (22180) were thoroughly explored. first of all, the list of derived nouns (2756) was prepared. then they were broken into their roots and affixes. from among 26 suffixes, in this paper, the 12 most frequents were selected (2461 derivatives), described and analysed. they are listed in a a-a any type of noun & adjective 10 "-ar" v-n v-a n-n n-a any type of noun & adjective 11 "-eʃ" v-n a-n any type of noun 12 "-ane" n/ aa/ d n/ dn any type of adjective & adverb food ## morpho-semantic analysis of selected suffixes in this part we will scrutinize our 12 most productive selected noun marker suffixes from a morpho-semantic point of view. more information about the other persian suffixes could be found in @xcite . ## conclusion morpho-semantic analysis of a selection of 2461 derived nouns in farsnet showed 45 morphosemantic patterns and 17 morpho-semantic relations (such as "derivative agent of base", "derivative location of base", etc.) for 12 most productive suffixes. considering that only 2 words out of 2461 (0.08%) did not fall into the patterns, it could be concluded that the patterns have successfully provided the foundations for establishing automatic relations between derived or complex nouns and their bases in farsnet. the coincident consideration of the words' morphological features such as their pos, their semantic and grammatical category (e.g. agent noun, participle noun, present participle, etc.) as well as recognizing the beginners of the bases (e.g. act, person, food, etc.) and their change after the affixation process have been the key criteria in formulating the relations which were especially crucial for the majority of studied suffixes that were polysemous. defining and codifying these morpho-semantic patterns leads us to coherent establishment of morpho-semantic relations in farsnet and hence has a remarkable developing impact on the applicability of the data base in machine translation, question answering systems, etc. although in this research the morpho-semantic relations are considered at the word level and not at the synset level, mapping the results to the relations formulated in other languages wordnets will provide a crosslingual validity, even if the morphological aspect of the relation is not the same in the mapped languages.