What requirement gathering techniques do you use: only questionnaires or also interviews, workshops, surveys?

For requirements gathering, I use a comprehensive approach, combining different techniques depending on the project and stakeholders:

• Interviews — allow for a deep understanding of the needs of key users and clients, uncovering hidden expectations.
• Workshops — effective for collaborative idea generation, requirements alignment, and task prioritization involving multiple stakeholders.
• Surveys and questionnaires — useful for collecting opinions from a large number of users, especially when quantitative data is needed.

I often start with interviews to identify main goals, then conduct workshops for detailing and alignment, and use surveys to validate hypotheses and gather feedback from a broad audience.

This approach helps to obtain a complete and accurate understanding of requirements, minimize misunderstandings, and improve the quality of the final solution.