Information retrieval models in the context of retrieval tasks

Information retrieval models are reviewed from the viewpoint of retrieval needs that cause different types of retrieval tasks. A generalized iterative query-response scheme of the retrieval process is presented. The characteristics of the system of retrieval mechanism models aimed at the support of retrieval tasks of different types, as well as at the development of the retrieval process using internal and external feedback, are stated. The use of models of multidimensional quantitative analysis based on coordinate indexing to perform external feedback is proposed.