Information retrieval may be defined as the process of retrieving the most suitable information as a response to the query being made by the user. In information retrieval, the search is performed based on metadata or context-based indexing. One example of information retrieval is Google Search in which, corresponding to each user query, a response is provided on the basis of the information retrieval algorithm being used. An indexing mechanism is used by the information retrieval algorithm. The indexing mechanism used is known as an inverted index. An IR system builds an index postlist to perform the information retrieval task.
Boolean retrieval is an information retrieval task in which a Boolean operation is applied to the postlist in order to retrieve relevant information.
The accuracy of an information retrieval task is measured in terms of precision and recall.
Suppose that a given IR system returns X documents when a query is fired. But the actual or...