Criteria for all articles:
For the poster project, you need at least five articles. Two must be research articles (includes meta-analyses and systematic reviews.)
A research paper reports the methods and results of an original study performed by the authors. The kind of study may vary (experiment, survey, interview, etc.), but in all cases, raw data have been collected and analyzed by the authors, and conclusions drawn from the results of that analysis. Research papers follow a particular format.