On-line Thematic and Metadata Analysis of Document Collection

We describe interactive search tools based on thematic and metadata analysis of a document collection. The tools provide the following facilities: estimation of the main themes discussed in a document set, interactive narrowing of a query, cross-language search, exploring the topic-time dependencies, and exploring the dependencies between authors of articles, scientific organizations and themes. We describe an algorithm for thematic and metadata analysis and show some examples of their applications. All the tools described are integrated into the large full-text information retrieval system UIS RUSSIA.