Which document can include copies of interviews for research purposes?

The appendix is a supplementary section of a report that provides additional information relevant to the main content. Including copies of interviews in the appendix is appropriate because this allows researchers to present detailed supporting materials without interrupting the flow of the main report. The appendix can contain a variety of documents—such as raw data, interview transcripts, questionnaires, or other pertinent information. By placing interviews in the appendix, it maintains clarity within the main report while still providing access to essential information that bolsters the research findings.

The other options serve distinct purposes in a report. The main report presents the core findings and discussions, while the abstract offers a brief summary of the research. The executive summary provides a concise overview of the report's conclusions and recommendations, making it easier for readers to grasp the essential points quickly. However, these sections are not suitable for including detailed raw data or transcripts.