方法对比

	开放获取期刊目录	期刊影响因子	PubMed 和 MEDLINE
领域	文献计量学	文献计量学	文献计量学
方法族	Process / pipeline	Process / pipeline	Process / pipeline
起源年份	2003	1955	1966
提出者	DOAJ Community (Swedish library consortium, later expanded to international consortium)	Eugene Garfield, Institute for Scientific Information (ISI)	National Library of Medicine (NLM), U.S. National Institutes of Health
类型	Database	Metric	Database
开创性文献	Directory of Open Access Journals. (2024). About DOAJ. Retrieved from https://doaj.org/	Garfield, E. (1972). Citation analysis as a tool in journal evaluation. Science, 178(4060), 471-479.	National Library of Medicine. (2024). PubMed: Home. Retrieved from https://pubmed.ncbi.nlm.nih.gov/
别名	DOAJ, Directory of Open Access	IF, JIF, Impact Factor, 2-year Impact Factor	PubMed, MEDLINE, NLM, PubMed Central
相关	5	5	5
摘要	The Directory of Open Access Journals (DOAJ) is a community-maintained, freely accessible directory of high-quality, peer-reviewed open-access journals and articles established in 2003. DOAJ indexes over 20,000 open-access journals across all disciplines (sciences, social sciences, humanities, arts) from diverse geographic regions. The directory serves researchers, librarians, and administrators as the authoritative curated list of legitimate open-access journals—differentiating quality open-access publications from predatory journals that lack genuine peer review. DOAJ quality seal, awarded to journals meeting stricter governance and transparency criteria, enables identification of the highest-caliber open-access publications.	Journal Impact Factor (JIF) is a metric developed by Eugene Garfield in 1955 and published annually by Clarivate Analytics through Journal Citation Reports (JCR). It measures the average citation frequency of articles published in a journal over a two-year window, serving as a proxy for journal prestige and influence. A journal's Impact Factor equals the number of citations received in year Y to articles published in Y-1 and Y-2, divided by the number of citable items published in that same window. Despite widespread adoption in research evaluation, Impact Factor has significant limitations and critics argue it conflates journal prestige with article quality.	PubMed is a free, publicly accessible literature database maintained by the National Library of Medicine (NLM), a division of the U.S. National Institutes of Health. It provides access to biomedical and life sciences literature from MEDLINE (the curated subset of ~30 million indexed journal articles), life science journals, in-process articles, and preprints. MEDLINE, established in 1966, is the gold standard for biomedical literature indexing, using MeSH (Medical Subject Headings), a hierarchical controlled vocabulary of ~33,000 terms. PubMed is the primary discovery tool for clinicians, researchers, and healthcare professionals worldwide seeking evidence-based information.