Bulgarian Language

Having being proposed for the fourth time, the QA at CLEF track has confirmed a still raising interest from the research community, recording a constant increase both in the number of participants and submissions. In 2006, two pilot tasks, WiQA and AVE, were proposed beside the main tasks, representing two promising experiments for the future of QA.Also in the main task some significant innovations were introduced, namely list questions and requiring text snippet(s) to support the exact answers. Although this had an impact on the work load of the organizers both to prepare the question sets and especially to evaluate the submitted runs, it had no significant influence on the performance of the systems, which registered a higher Best accuracy than in the previous campaign, both in monolingual and bilingual tasks. In this paper the preparation of the test set and the evaluation process are described, together with a detailed presentation of the results for each of the languages. The pilot tasks WiQA and AVE will be presented in dedicated articles.

The paper presents the semantic modeling of Bulgarian parts-of-speech within the theory of Head-driven Phrase Structure Grammar (HPSG). The parts-of-speech are divided into two main groups:  referents and events. The referents are indicated by the nouns, while the events are presented through verbs, prepositions, adjectives, numerals, adverbs. Since HPSG is a monostratal linguistic theory, the morphosyntactic and semantic information are presented at one level and in close relation to each other. In such a context, the challenge is that Bulgarian is a language with rich morphology, and the model has to balance between the grammar and semantics respectively.

The paper discusses the syntactic relations within Bulgarian complex words with a verbal root as head and nominal or adverbial root as dependant. The parts-of speech considered are verbs and verbal nouns. The corpus-based survey shows that verbal nouns allow more often the existence of word-internal arguments than verbs. The data presents both cases: when any word-external arguments are blocked, and when such arguments are allowed.

The paper focuses on the sense annotation of BulTreeBank. It discusses three levels of annotation: valency frames, lexical senses and DBPedia URIs. The lexical sense annotation is considered in more detail and in relation to the other two processes. Special attention is paid to the quality validation with respect to two aspects: inter-annotator agreement and cross-resource control.