In literature research, which source would be considered a primary source?

The selection of the research report of a clinical trial in a research journal as a primary source is justified because primary sources provide direct evidence or firsthand accounts of a particular event or study. In this context, a research report presents original findings, methodologies, and data derived directly from the clinical trial. This allows readers to access the initial results and processes undertaken by the researchers, making it the foundational work upon which further studies and discussions are built.

Secondary sources, such as a book summarizing various studies or a review article, synthesize findings from multiple primary sources, offering interpretations or analyses rather than original data. Conversely, anecdotal experiences, while they can provide insights or inform practice, do not offer the systematic analysis or rigor associated with primary research. Thus, the research report stands out as the key primary source for literature research in this scenario.