Introduction: Recently, the problem of diversification of search results has attracted a lot of attention in the information retrieval and Web search research community. For multi-faceted or ambiguous queries, a search engine is generally favoured if it is able to identify relevant documents on a wider range of different aspects. Method: We…

Introduction: In the big data age, we have to deal with a tremendous amount of information, which can be collected from various types of sources. For information search systems such as Web search engines or online digital libraries, the collection of documents becomes larger and larger. For some queries, an information search system needs to…