Interviewing is a technique to elicit information, opinions, or feedback from stakeholders by asking them questions and listening to their responses. Interviewing can be used to clarify or validate requirements, resolve conflicts or misunderstandings, build rapport and trust, and explore complex or sensitive issues. A good time to consider using the interviewing method is when there are communication challenges among stakeholders, such as different perspectives, expectations, or interests. Interviewing can help to overcome these challenges by providing a direct and personal communication channel, allowing the interviewer to tailor the questions and responses to each stakeholder, and facilitating a deeper understanding of the stakeholder's needs and concerns. The other options are not good times to consider using the interviewing method. Attempting to obtain sign-off on requirements from stakeholders is not an elicitation activity, but a validation activity that requires formal documentation and approval. There is not enough time to gather requirements from many different sources is a constraint that limits the use of interviewing, as it is a time-consuming and resource- intensive technique that can only involve a few stakeholders at a time. Assembling a requirements traceability matrix is not an elicitation activity, but an analysis activity that involves linking the requirements to their sources and deliverables using a tool or document. References: PMI-PBA Examination Content Outline, page 10; PMI-PBA Reference List, page 1, BABOK Guide v3, page 50.