Anderson K. A confusion of journals - what is PubMed now? The Scholarly Kitchen September 7, 2017
PubMed Central used to be a credentialing system, an online port of the MEDLINE index. This shift of medium quickly made it a search engine, but one built on a manual and highly curated index. Then it was discovered that it is including articles published in journals whose publishers are considered predatory. Although these articles appear in PubMed (often after a delay), the titles are not indexed by Medline and are difficult to find. PubMed’s brand has long been muddled in ways that pass lower-quality works through the system under cover of prestige. This has real consequences.