1, define the purpose of information retrieval.

2. Make clear what the theme concept is.

3. Analyze the relationship between the concepts of each theme.

4. Clear retrieval requirements include specific requirements such as the subject range, type, language and age of the required information.

Data expansion:

Information retrieval is the main way for users to query and obtain information, and it is also the method and means to find information. Information retrieval in a narrow sense only refers to information search.

In other words, users can use certain methods and retrieval tools to find the information they need from the information collection according to their own needs. Information retrieval in a broad sense is a process of processing, sorting, organizing and storing information in a certain way, and then accurately finding out relevant information according to the specific needs of information users.

Also known as information storage and retrieval. Generally speaking, information retrieval refers to information retrieval in a broad sense. Information retrieval originated from the library's reference service and abstract indexing, and first developed in the second half of19th century. By the 1940s, indexing and retrieval had become an independent tool and user service project of libraries.

With the advent of the first electronic computer in the world in 1946, computer technology gradually entered the field of information retrieval, and was closely combined with information retrieval theory; Off-line batch information retrieval system and online real-time information retrieval system.

They have been successfully developed and commercialized. From 1960s to 1980s, with the promotion of information processing technology, communication technology, computer and database technology, information retrieval developed rapidly in the fields of education, military and commerce, and was widely used.

Information retrieval can be divided into broad sense and narrow sense. Information retrieval in a broad sense is called "information storage and retrieval", which refers to the process of organizing and storing information in a certain way and finding out relevant information according to the needs of users.

Information retrieval in a narrow sense is the second half of "information storage and retrieval", usually called "information retrieval" or "information search", which refers to the process of finding out the relevant information needed by users from the information collection. Information retrieval in a narrow sense includes three aspects: understanding the information needs of users, information retrieval technology or methods, and meeting the needs of information users.