What is the most critical differentiating factor between a peer-reviewed article and a secondary source compilation of research?

The most critical differentiating factor between a peer-reviewed article and a secondary source compilation of research is the presence of original research and a rigorous evaluation process. A peer-reviewed article presents original research findings, meaning the authors conducted their own study, experiment, or analysis and are reporting the results for the first time. Before publication, the article undergoes a process of peer review, where experts in the same field critically evaluate the methodology, results, and conclusions to ensure the research is sound and valid. In contrast, a secondary source compilation of research, such as a review article or textbook, synthesizes and summarizes the findings of existing research. It does not present new original research but rather provides an overview and interpretation of previous studies. Secondary sources may undergo an editorial review process, but they do not involve the same level of scrutiny by independent experts focused on the originality and validity of the research itself.