BulQA: Bulgarian–Bulgarian Question Answering at CLEF 2005 Kiril Simov and Petya Osenova Linguistic Modelling Laboratory, Bulgarian Academy of Sciences, Bulgaria kivs@bultreebank.org, petya@bultreebank.org Abstract This paper describes the architecture of a Bulgarian–Bulgarian question answering system — BulQA. The system relies on a partially parsed corpus for answer extraction. The questions are also analyzed partially. Then on the basis of the analysis some queries to the corpus are created. After the retrieval of the documents that potentially contain the answer, each of them is further processed with one of several additional grammars. The grammar depends on the question analysis and the type of the question. At present these grammars can be viewed as patterns for the type of questions, but our goal is to develop them further into a deeper parsing system for Bulgarian. The CLaRK System is used as an implementation platform — [5]. Categories and Subject Descriptors H.3 [Information Storage and Retrieval]: H.3.1 Content Analysis and Indexing; H.3.3 Infor- mation Search and Retrieval; H.3.4 Systems and Software; H.3.7 Digital Libraries; H.2.3 Database ManagementLanguages [Query Languages] General Terms Measurement, Performance, Experimentation Keywords Question answering, Answer support, Pattern grammars 1 Introduction This paper describes the architecture and the linguistic processing of a question answering system for Bulgarian — BulQA. The system has three main modules: Question analysis module, Interface module, Answer extraction module. The Question analysis module deals with the syntactic and semantic interpretation of the question. The result of this module is independent from task and domain representation of the syntactic and semantic information in the question. The Interface module bridges the interpretation received from the first module to the input necessary for the third module. The Answer extraction module is responsible for the actual detection of the answer in the corresponding corpus. This architecture has the advantage that it allows the poly-usage of the same modules in different tasks, such as Bulgarian as source language in a multilingual question answering, or Bulgarian as a target language. In fact, only the Interface module has to be re-implemented in order to tune the connection between Bulgarian modules and the modules for the other languages.