HS Easy practical guide
Investigations: the importance of using open questions
A practical guide to using open questions in workplace incident and near-miss investigations, with examples that help gather fuller accounts without assuming the answer.
The short answer
Open questions invite people to describe what they saw, did and understood in their own words. They can uncover useful detail and reduce assumptions. Use them first, then use focused follow-up questions to clarify times, locations, equipment and actions.
A good investigation needs a clear account before causes and actions are considered. Open questions help the investigator understand events from the person’s perspective rather than steering them towards a preferred answer. They are useful after accidents, incidents, near misses, unsafe conditions and equipment faults across all workplaces.
What is an open question?
An open question cannot usually be answered with just “yes”, “no” or one short fact. It encourages explanation. This can reveal conditions, decisions, changes and concerns that may not appear in an initial report.
- Open: “What happened when you started the task?”
- Closed: “Were you trained to do the task?”
- Use neutral wording and allow time to answer.
Why open questions matter in investigations
Open questions help avoid filling gaps with assumptions. They may identify differences between the planned method and the work actually carried out, or show that several factors contributed. A person’s account is evidence to check, not proof on its own.
- Capture what the person noticed, not just the outcome.
- Identify documents, equipment, people or locations to examine.
- Avoid implying blame or the answer you expect.
Start broad, then narrow the detail
Begin with a broad invitation, then use follow-up questions to establish the sequence. Closed questions still have a role when checking a specific fact, but they should not replace the fuller account.
- Start: “Please talk me through the shift up to the event.”
- Probe: “What changed from the normal process?”
- Check: “Was the guard in place at that point?”
Useful open-question examples
Questions should fit the event and the person’s role. Ask about what they observed and understood, rather than asking them to diagnose the cause. Keep the language familiar to the workplace.
- “What did you see, hear or notice before the incident?”
- “How was the task normally planned and carried out?”
- “What made it difficult to complete the task safely?”
Record answers accurately and test the evidence
Write down the account as accurately as possible, separating what was said from the investigator’s interpretation. Compare accounts with physical evidence, relevant records and the work area. Explain any uncertainty where information cannot be confirmed.
- Record dates, times, locations and people involved where known.
- Ask follow-ups when wording is unclear or the sequence is incomplete.
- Keep corrective actions linked to evidence, not assumptions.
Key takeaways
Open questions are a practical starting point for fairer, more useful investigations. They help people explain the real work and conditions around an event. Follow them with focused checks, examine supporting evidence and record uncertainty rather than forcing a conclusion.
Frequently asked questions
What is the difference between open and closed questions in an investigation?
Open questions invite explanation, such as “What happened next?” Closed questions seek a limited answer "yes" or "no", such as “Was the machine isolated?” Start open to gather the account, then use closed questions to confirm specific details.
Can closed questions still be used in an incident investigation?
Yes. They are useful for checking a known detail, such as a time, location or whether a control was present. Used too early or too often, they can restrict the account or suggest the answer expected.
How can an investigator avoid leading questions?
Ask what the person saw, did or understood instead of building an assumption into the question. For example, ask “What condition was the floor in?” rather than “Was the floor wet because it had not been cleaned?”
How do open and closed questions begin?
Open questions usually start with What, Where, When, How or Who. Closed questions often start with words such as Did, Do, Does, Was or Is and usually lead to a short or yes/no answer.
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General information only. Review current HSE guidance, your own procedures and the conditions at your workplace.