UK Document retrieval is defined as the matching of some stated user query against useful parts of free-text records . These records could be any type of mainly unstructured text , such as bibliographic records , newspaper articles , or paragraphs in a manual. User queries could range from multi-sentence full descriptions of an information need to a few words and the vast majority of retrieval systems currently in use range from simple Boolean systems through to systems using statistical or natural language processing .
Figure illustrates the manner in which documents are retrieved from various sources.
The document retrieval process. Several events have recently occurred that are having a major effect on research in this area. First, computer hardware is more capable of running sophisticated search algorithms against massive amounts of data, with acceptable response times. These two events have contributed to create an interest in accelerating research to produce more effective search methodologies , including more use of natural language processing techniques. This group has found phrases to be useful in retrieval for smaller collections, or for collections in a narrow domain.