Journal articles are either primary or secondary research. Primary research refers to original research. When searching for journal articles you cannot use "primary" as a search term to help you locate journal articles containing primary research. You must skim read the article looking for mentions of methods and then determine of the method was new, or original, research or if it is a summary of other researchers' research.
Articles that are summaries of most research done on a single topic are considered secondary research; they are also called Literature Reviews. Again, "secondary" and "literature review" are not useful search terms because these words are entirely too common. Every primary research article has a small portion of the article devoted to a literature review before presenting their methods and findings.
