The head of the department and the Client had a meeting to discuss a potential project. The Client had a Business Case ready and wanted to sign the contract. However, the high-level requirements, project description, boundaries, and key deliverables weren't described either in the Business Case or in the draft Contract. Therefore, they invited the main project stakeholders and subject matter experts for a meeting at the company's main conference room next Tuesday. What kind of data-gathering technique do they plan on using and why explain.