ISI refers to the most influential research achievements, which means that a large number of documents reporting these achievements are cited by other documents. Therefore, as a retrieval tool, SCI has set up a unique "CitationIndex", which is contrary to the conventional practice of other retrieval tools to retrieve documents by subject or classification. That is, through the reference of the current document to the previous document, the correlation between documents and the influence of the previous document on the current document are explained.
The above characteristics of SCI make SCI not only a document retrieval tool, but also a basis for scientific research evaluation. The total number of papers collected by SCI in scientific research institutions reflects the scientific research level of the whole institution, especially the basic research; The number of papers collected and cited by SCI reflects his research ability and academic level.
In addition, ISI publishes JCR(journalicitationreports) every year. JCR counts and calculates the citation and cited data of 4,700 journals, including 3,500 journals included in SCI, and defines the impact factors and other indicators to be reported by each journal. The impact factor of a periodical refers to the average number of citations in the previous two years. The higher the impact factor of a publication, the higher the citation rate of its published documents, which on the one hand shows that the research results reported by these documents have great influence, on the other hand, it also reflects the high academic level of the publication. Therefore, JCR has become a regular evaluation tool because of its large number of regular statistical data and calculated influencing factors. Libraries can make periodical introduction policies according to the data provided by JCR; Authors can decide the direction of submission according to the ranking of impact factors of journals. EI is the abbreviation of TheEngineeringIndex. EI was founded in 1884 and published by American Engineering Information Company .. EI is a comprehensive retrieval tool in the field of engineering technology, covering such disciplines as electricity, automatic control, power, machinery, instrumentation, material science, agriculture, bioengineering, mathematics, medicine, chemical engineering, food, computer, energy, geology and environment.
Ei Compendex is the earliest source of engineering abstracts in the world. The index information of 500,000 abstracts added to Ei Compendex database every year comes from 565,438+000 engineering journals, conference collections and technical reports. The documents collected by Ei Compendex cover all engineering fields, of which about 22% are conference documents and 90% are in English. Ei Company began to collect China periodicals from 1992. 1998 Ei Set up Ei China Mirror Station in Tsinghua University Library. ISTP is a scientific index &; TechnicalProceedings is the abbreviation of American scientific information research.
One of the two databases (ISTP and ISSHP) in the scientific planning network. Specialized in collecting conference documents of various important international natural science and technology conferences, including general conferences, symposiums, research conferences, seminars, conferences, etc. The subjects involved are basically the same as SCI.
The number of papers collected by ISTP is related to the number of important international academic conferences attended by scientific and technical personnel or the number of papers submitted for publication. Papers published by China scientific and technical personnel at international conferences held abroad account for 64.44% of the total papers included.
Among the three retrieval systems ISTP, EI and SCI, SCI can best reflect the research level and paper quality of basic disciplines. The retrieval system contains more comprehensive sci-tech periodicals, which can be said to be the essence of high-quality excellent papers in various disciplines. This retrieval system has always been the center and focus of the world's scientific and technological circles. ISTP and Ei retrieval systems are relatively loose in evaluating the quality standards of scientific papers and periodicals.