What type of article are you looking for or looking at?
These categories are not rigid and some of them overlap. Here are some characteristics to help identify the article type:
Open Access (OA)
Research articles:
Peer reviewed (or Refereed) articles:
PrePrint articles:
Review articles:
Conference papers:
Technical reports: (not peer reviewed)
Trade publication articles: (not peer reviewed)
Popular articles: (not peer reviewed)
Websites, press releases, encyclopedia entries:
Q. What is peer review?
A. For an article to be published in an academic journal, it must be examined by experts in the field. They determine whether the information is reliable, well researched, and of interest to others who study that subject. Click on image for 5 min video explanation of peer review from North Carolina State University.
Q. How can I tell if an article is peer-reviewed?
A. There are several ways to determine if an article is refereed (peer-reviewed). The best way is to read the publisher's policies at the journal website (look for Peer Review or Editorial Policy, Submission or Author Guidelines). Ulrich's Global Serials Directory also indicates whether a journal is refereed/peer-reviewed. Beware that peer-reviewed journals also include content that is not peer reviewed, such as letters and book reviews. A peer-reviewed article will usually show a string of dates, usually either near the abstract or at the bottom of the 1st page of the PDF version or at the end of the article, showing when the article was submitted, revised, and accepted.
Databases may offer the ability to filter search results to display only peer-reviewed publications. Search engines, like Google Scholar, includes both peer-reviewed and "grey" literature that is not commercially published and may not be peer reviewed.
Authority
Who created the resource? Are the author, organization, affiliations, and publisher clearly shown? If the page is web-based does it link to information about the organization? Does the author have credentials or expertise in the subject matter? Is the resource from a government agency, university, company, non-profit organization?
Accuracy
Is the information contained in the source properly cited? Is there a bibliography or reference list? Can you verify the information in other sources? Is the information free of grammatical, spelling, and typographical errors? Is the statistical data clearly explained? Are charts and graphs properly represented and cited?
Objectivity
Is there any bias? Is the resource free of advertising? If there is advertising, is it clearly separate from content? Is the sponsoring organization motivated to report facts from a singular perspective?
Currency
When was the resource created? When was it updated/ revised? How current is the information cited?
Coverage
Is the information complete? Does it cover the subject in depth and provide context? Does it match your information needs?
These criteria were adapted from a worksheet used by Harvard University's Widener Science Library.
Q. What is a primary source?
A. Primary documents are the original source materials.
In the sciences, lab data, lab notebooks, and original test protocols are considered primary documents. Source code and release notes, field observation notes or images are also primary documents. Journal articles are primary or first reports of research.
Q. What is a secondary source?
A. Secondary sources comment, analyze, or otherwise rely on primary sources.
Books, encyclopedias, and news articles are secondary sources because they describe what you will find in the primary sources.
Watch Pyrates: Truth be told for a perspective on primary sources in history!