Here's a chart by our former library director, which provides easy comparison between scholarly and popular interest publications:
There is absolutely nothing wrong with journalism. However, for a college-level research paper, a professor usually wants to see higher level research literature and not just reportage.
Even beyond "scholarly," your instructor will often require that you take your research articles only from "Peer-Reviewed" Journals. Additionally, those articles from peer-reviewed journals must often be "Research Studies" or "Primary Literature." Look at the other tabs above for more clarification.