The Polish Wordnet, plWordNet, has been in steady development for five years. We are building it from scratch, all the time making provisions for its general compatibility with the other major wordnets. We are very close to reaching a milestone of 100000 lexical units in 70000 synsets. In addition to a fairly comprehensive coverage of common nouns, there already is in plWordNet a significantly built-up verb component, and a similarly enlarged adjective component is under construction. We present the background, the assumptions, the relation set (essential for any wordnet, and central for our inflectionand derivation-rich language) and the current state of the project, and we map the near future.

Approaching plWordNet 2.0

Wordnets are built of synsets, not of words. A synset consists of words. Synonymy is a relation between words. Words go into a synset because they are synonyms. Later, a wordnet treats words as synonymous because they belong in the same synset $$\ldots$$ ? Such circularity, a well-known problem, poses a practical difficulty in wordnet construction, notably when it comes to maintaining consistency. We propose to make a wordnet a net of words or, to be more precise, lexical units. We discuss our assumptions and present their implementation in a steadily growing Polish wordnet. A small set of constitutive relations allows us to construct synsets automatically out of groups of lexical units with the same connectivity. Our analysis includes a thorough comparative overview of systems of relations in several influential wordnets. The additional synset-forming mechanisms include stylistic registers and verb aspect.

/pdf/the-chicken-and-egg-problem-in-wordnet-design-synonymy-1wb1q3155b.pdf

The chicken-and-egg problem in wordnet design: synonymy, synsets and constitutive relations

Wordnets are lexico-semantic resources essential in many NLP tasks. Princeton WordNet is the most widely known, and the most influential, among them. Word- nets for languages other than English tend to adopt unquestioningly WordNet's struc- ture and its net of lexicalised concepts. We discuss a large wordnet constructed inde- pendently of WordNet, upon a model with a small yet significant difference. A map- ping onto WordNet is under way; the large portions already linked open up a unique perspective on the comparison of similar but not fully compatible lexical resources. We also try to characterise numerically a wordnet's aptitude for NLP applications.

Beyond the Transfer-and-Merge Wordnet Construction: plWordNet and a Comparison with WordNet

Semantic relations among adjectives in Polish WordNet 2.0: a new relation set, discussion and evaluation Adjectives in wordnets are often neglected: there are many fewer of them than nouns, and relations among them are sometimes not as varied as those among nouns or verbs. Polish WordNet 1.0 was no exception. Version 2.0 aims to correct that. We present an overview of a much larger set of lexical-semantic relations which connect adjectives to the other parts of the network. Our choice of relations has been motivated by linguistic considerations, especially the concerns of the Polish lexical semantics, and by pragmatic reasons. The discussion includes detailed substitution tests, meant to ensure consistency among wordnet editors.

/pdf/semantic-relations-among-adjectives-in-polish-wordnet-2-0-a-tap9u7opap.pdf

Semantic relations among adjectives in Polish WordNet 2.0: a new relation set, discussion and evaluation

The paper presents construction of \emph{Derywator} -- a language tool for the recognition of Polish derivational relations. It was built on the basis of machine learning in a way following the bootstrapping approach: a limited set of derivational pairs described manually by linguists in plWordNet is used to train \emph{Derivator}. The tool is intended to be applied in semi-automated expansion of plWordNet with new instances of derivational relations. The training process is based on the construction of two transducers working in the opposite directions: one for prefixes and one for suffixes. Internal stem alternations are recognised, recorded in a form of mapping sequences and stored together with transducers. Raw results produced by \emph{Derivator} undergo next corpus-based and morphological filtering. A set of derivational relations defined in plWordNet is presented. Results of tests for different derivational relations are discussed. A problem of the necessary corpus-based semantic filtering is analysed. The presented tool depends to a very little extent on the hand-crafted knowledge for a particular language, namely only a table of possible alternations and morphological filtering rules must be exchanged and it should not take longer than a couple of working days.

/pdf/recognition-of-polish-derivational-relations-based-on-506opq1i37.pdf

Recognition of Polish Derivational Relations Based on Supervised Learning Scheme

Semantic relations between verbs in Polish WordNet 2.0 The noun dominates wordnets. The lexical semantics of verbs is usually under-represented, even if it is essential in any semantic analysis which goes beyond statistical methods. We present our attempt to remedy the imbalance; it begins by designing a sufficiently rich set of wordnet relations for verbs. We discuss and show in detail such a relation set in the largest Polish wordnet. Our design decisions, while as general and language-independent as possible, are mainly informed by our desire to capture the nature and peculiarities of the verb system in Polish.

/pdf/semantic-relations-between-verbs-in-polish-wordnet-2-0-2rndm00c2m.pdf

Bożena Hojka

Papers

Semantic Relations Between Verbs in Polish Wordnet 2.0