1. Internal characteristics
Meaning: system classification language - classification index; subject language (title word - title word index. Unit word - unit word index, keyword - keyword index , thesaurus - thesaurus index); code language (molecular formula, etc. - molecular formula index and other special indexes, structural formula - structural formula index).
Purpose: Search for the document title (i.e. document title), author name, publisher, report number, patent number, etc.
2. External features
Meaning: The search language for external features of documents mainly refers to the title (title), author name, publisher, report number, patent number, etc. of the document. Arrange different documents according to the alphabetical order of the article title and author name, or arrange them in numerical order according to the report number and patent number, forming a search language that meets the user's needs through the search method of article title, author and number.
Purpose: Search for the document title (i.e. document title), author name, publisher, report number, patent number, etc.
Extended information
The literature retrieval methods are as follows:
1. Author route
Many retrieval systems have author indexes, institutions (institutions) The patent document retrieval system has a patentee index, and the method of using these indexes to search in alphabetical order from the names of authors, editors, translators, patentees, or institution names is collectively referred to as the author route.
2. Title approach
Some retrieval systems provide ways to search in title order, such as book title catalogs and journal title catalogs.
3. Classification approach
Retrieve documents according to the subject classification system. This approach is classified and sorted with the knowledge system as the center. Therefore, it can better reflect the systematic nature of the discipline and reflect the affiliation, derivation and parallel relationship between the discipline and things. It is convenient for us to search for literature materials from the scope of the discipline, and can start To the effect of "paradigmatic". Retrieval of literature materials from classification methods mainly uses classification catalogs and classification indexes.
Baidu Encyclopedia-Document external characteristics