Your professor may require you to find a "primary" or "unfiltered" research article. These terms are very similar and just refer to original research rather than a systematic review, meta analysis or secondary research. A primary source is defined as a "source whose author originated or is responsible for generating the ideas published." CINAHL and many of the other databases have a limiter allowing to limit the results to research articles (SuperSearch does not though it contains lots of research articles). The majority of these will be primary or unfiltered but you will want to look at the article for yourself to be sure and avoid those labeled as systematic review or meta analysis. See attached handout for pictures and more information.