Peer Reviewed research: A manuscript that has gone through either single or double blind review by usually three experts in the field and has been accepted as good quality work. It can either be an empirical/primary article or a review article.
Research article: An empirical study that has successfully gone though the process of peer-review
Review article: A secondary article that synthesizes information from several primary articles and has successfully gone through the process of peer-review
Preprint: Either a primary/empirical or review/secondary article that is in the process of being peer-reviewed. Repositories like ArXIV, BioXIV and MedXIV (Not curated collections) to allow for pre-prints to be uploaded to allow for immediate access to research. It is the responsibility of the user of such pre-prints to vet the information in them and to regularly monitor the pre-print repository to follow the status of the pre-print.
Popular media or website: Online resources where individuals share their personal opinions (not peer-reviewd). It is the responsibility of the research to verify content before sharing it any further.
Infodemic: Not a real type of article but a term used to refer to why it is hard to keep track of all the information about COVID-19 basically an information - pandemic!
While searching for primary literature it is important to look at journals with a reputation of publishing high quality work. These tend to have high impact factors and are sometimes locked behind paywalls. At Oxy, it is possible to access papers from such journals by setting up an Interlibrary Loan account. It is also recommended that you start reading review papers that are related to you research interests. Since most fields are rapidly producing more and more literature, you also need to pay attention to accessing the most recently published worked in the area of your interest. Here is a quick definition of some terms that you will hear from faculty regarding searching for literature:
Journal Impact Factor/Impact Factor: The impact factor is a measure of the frequency in which the average article in a journal is cited in a particular year. Impact factors measure the impact of the journal, not the impact of individual articles.
Eigenfactor: A value used to rank the likelihood that a journal will be used, or how important it is(a kind of popularity index).
H-index: The H-index is a measure of an individual's scientific productivity.
Citation number: The number of times an article has been cited in another published work. The citation number is calculated using different algorithms depending on who is generating the data.