According to the carrier type, it can be divided into writing type, printing type, miniature type, audio-visual type and electronic document.
According to the publishing type, it can be divided into 1 books, 2 periodicals, 3 conference documents, 4 scientific reports, 5 government publications, 6 patent documents, 7 technical standards, 8 product materials, 9 dissertations and 10 technical files.
According to the processing depth and content nature of the document content, 1 first-level document 2, second-level document 3, third-level document 4 and zero-level document.
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Commonly used book classification methods include China Library Classification (Chinese Library Classification), Renmin University of China Library Classification (National People's Congress Law) and China Academy of Sciences Library Classification (Ketu Law).
Database retrieval method
1 keyword method 2 keyword method 3 title method 4 author method 5 classification method
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Evaluation index of retrieval effect:
Recall rate and accuracy
I don't know the retrieval rules
Adjustment of retrieval strategy
1 can be used to expand the search scope and improve the recall.
-Add various forms of free search and use the OR operator.
-reduce the use of AND or NOT.
-Changing from phrase retrieval to fuzzy retrieval
-Search by word truncation
-Adjust limited fields, such as changing the title or keyword field to literature or all fields.
-appropriately relax restrictions. For example, expanding the time range and canceling the restrictions on literature types.
-Use other retrieval systems for retrieval.
-Use more search methods to search.
2 methods that can be used to narrow the search scope and improve the accuracy.
-Add a topic concept surface AND search with the AND operator.
-Use positional operators or exclude irrelevant concepts with NOT.
-Search for phrases accurately.
-Choose a more precise concept of subordination
-Add restrictions, such as narrowing the release time range. There are limited types of literature. The original language. Restrict core journals, etc.
-Limited field search, such as limiting search terms to specific fields, such as title keywords or subject words.
-Limit the search to a subset or font.
If there is a retrieval system with a keyword retrieval method, use the keyword retrieval method, matching with specific sub-topic phrases, weighted retrieval, non-extended retrieval, using lower keywords, and joint retrieval of keyword method and other methods, etc.
Document Retrieval Steps (Rules)
1 Analyze the retrieval subject and define the retrieval requirements.
2. Select the retrieval tool and determine the retrieval method.
3. Select retrieval methods and keywords, and formulate retrieval strategies.
4. Evaluate the retrieval results and optimize the retrieval strategy.
5. Literature screening to obtain the original literature.
Literature retrieval technology
1 Boolean logic retrieval
2. Intercept retrieval
3 limited search
4 phrase retrieval
5 extended retrieval
6 location retrieval
Search and Application of Medical Subject Words (MeSH)
Principle of word selection
1 First, select special words, second, select collocations, and third, select superordinate words or synonyms.