Evaluating online articles is more challenging because physical factors like graphics are absent. Some databases allow you to narrow your search to only scholarly periodicals so you can be sure what kind of results you're getting.
If you're not sure, you can also search for the journal publisher's website (try a Google search for the journal's name + "publisher") which will give you information about that journal, usually including whether it is peer-reviewed or not. Note that the journal may even have a Wikipedia page which may give you useful information about the journal.
Periodical is a term used to describe any publication that is published multiple times (periodically). Periodicals include materials such as popular magazines, scholarly journals, and newspapers.
It is important to understand the difference between a popular and a scholarly periodical. When you are doing research, most of your sources should be scholarly.
Often popular periodicals are called magazines and scholarly periodicals are called journals. Many times it will be acceptable to use some popular material, but research papers should not be based solely on popular literature.
|Criteria||Popular Magazine||Trade Journal||Scholarly Journal|
|Content||Secondary discussion of someone else's research; may include personal narrative or opinion; general information, purpose is to entertain or inform.||Current news, trends and products in a specific industry; practical information for professionals working in the field or industry.||In-depth, primary account of original findings written by the researcher(s) or reviews of original research; very specific information, with the goal of scholarly communication.|
|Author||Author is frequently a journalist paid to write articles, may or may not have subject expertise.||Author is usually a professional in the field, sometimes a journalist with subject expertise.||Author's credentials are provided; usually a scholar or specialist with subject expertise.|
|Audience||General public; the interested non-specialist.||Professionals in the field; the interested non-specialist.||Scholars, researchers, and students.|
|Language||Vocabulary in general usage; easily understandable to most readers.||Specialized terminology or jargon of the field, but not as technical as a scholarly journal.||Specialized terminology or jargon of the field; requires expertise in subject area.|
|Layout & Organization||Informal; may include non-standard formatting. May not present supporting evidence or a conclusion.||Informal; articles organized like a journal or a newsletter. Evidence drawn from personal experience or common knowledge.||Structured; includes the article abstract, goals and objectives, methodology, results (evidence), discussion, conclusion, and bibliography. (**The structure may be more implicit in a humanities-oriented article)|
|Accountability||Articles are evaluated by editorial staff, not experts in the field; edited for format and style.||Articles are evaluated by editorial staff who may be experts in the field, not peer-reviewed*; edited for format and style.||Articles are evaluated by peer-reviewers* or referees who are experts in the field; edited for content, format, and style.|
|References||Rare. Little, if any, information about source materials is given.||Occasional brief bibliographies, but not required.||Required. Quotes and facts are verifiable.|
|Paging||Each issue begins with page 1.||Each issue generally begins with page 1.||Page numbers are generally consecutive throughout the volume.|
Based on Scholarly vs. Popular Materials by Amy VanScoy, NCSU Library