When you are determining whether or not the article you found is a peer-reviewed article, you should consider the following.
Does the article have the following features?
Is the journal in which you found the article published or sponsored by a professional scholarly society, professional association, or university academic department? Does it describe itself as a peer-reviewed publication? (To know that, check the journal's website).
Did you find a citation for it in one of the databases that includes scholarly publications? (Academic Search Complete, PsycINFO, etc.)? Read the database description to see if it includes scholarly publications.
In the database, did you limit your search to scholarly or peer-reviewed publications? (See video tutorial below for a demonstration.)
Is the topic of the article narrowly focused and explored in depth?
Is the article based on either original research or authorities in the field (as opposed to personal opinion)?
Is the article written for readers with some prior knowledge of the subject?
If your field is social or natural science, is the article divided into sections with headings such as those listed below?