A case study interview can produce an hour of enthusiastic conversation and still leave the writer without a clear account of what happened. General questions about satisfaction often miss the decisions, constraints and evidence needed for a useful story.
Good customer case study questions follow the work from its starting point to its outcome. They leave room for the customer's own priorities and give the writer a way to distinguish an observation from a claim that needs further support.
Begin with the work before the project
Ask the customer to describe the process they were using and the point where it became difficult. “Walk me through how the team handled this before” invites more detail than “What problems did our product solve?”
Explore who was involved, what mattered to them and what alternatives they considered. Do not assume that every stakeholder shared the same reason for changing the process.
GOV.UK's guidance on learning about user needs encourages understanding people's goals and circumstances. A marketing interview has a different purpose from service research, but it still benefits from starting with the customer's real situation.
Ask how the decision became practical
Use a small set of questions to follow the decision into the actual work:
- “What had to be ready before you could begin?”
- “Who needed to agree, and what did they need to know?”
- “Which part took more attention than you expected?”
- “What changed after the first attempt?”
You do not need to ask them all in order. If an answer reveals a useful detail about training, responsibility or preparation, follow that thread before moving on.
Follow the customer's answers instead of rushing through a prepared list. A small detail about training or responsibility can explain more than a rehearsed description of a smooth partnership.
Nielsen Norman Group's article on why user interviews fail describes problems with leading questions and poorly chosen methods. Avoid asking the customer to confirm a success narrative you wrote before the interview.
Examine the evidence behind the result
If the customer reports a change, ask how they noticed it. For a measured result, establish the baseline, period, definition and source. Ask whether other changes happened at the same time and whether the figure applies to the whole organisation or one team.
For a qualitative improvement, ask for an example of the work now. “What can someone do differently?” may reveal a practical outcome that does not need an invented percentage.
GOV.UK's guidance on contextual research and observation shows the value of understanding activity in its working context. Where appropriate and permitted, ask for a demonstration or supporting record rather than relying entirely on memory.
Finish with limitations and approval
Ask what the customer would tell another organisation considering the same approach. Invite them to mention what did not change and what circumstances made the project suitable. Those answers help readers assess fit rather than assume the outcome is universal.
Explain the review process before ending the conversation. Confirm who needs to approve the story, which claims require checking and what identity details may be published. An interview recording is source material, not automatic permission for every use.
Once approved, a short excerpt can become a testimonial in Mirror App's Reviews Widget on a relevant website page. Keep that excerpt connected to the full story's meaning, especially when the result depends on conditions that need explanation.
Follow an answer far enough to make it usable
Imagine a customer says, “The new process saved us a lot of time.” Publishing that sentence immediately leaves the reader to guess what changed. A useful follow-up is, “Which part of the work takes less time now?” The answer may reveal that the customer means preparing one weekly document, rather than the entire team's workload.
Continue with questions that fit the answer: Who prepared that document before? What did they have to collect? What happens differently now? Is there a record that would help us check the comparison? The conversation should become more concrete without pressuring the customer to supply a percentage.
If the customer cannot measure the difference, retain a qualitative account. “We no longer ask three colleagues for the same update” can describe an observable change without pretending that the business has calculated a financial return. If the customer offers a number, ask what it includes and whether it comes from a record or an estimate.
Another answer worth exploring is, “The implementation was easy.” Ask the customer to walk through the first week. You may learn that a member of their team spent substantial time preparing information before the service began. That detail does not undermine the story; it helps another buyer understand the preparation that made the experience work.
Leave the interview with a usable evidence record
Before ending, repeat the main points in ordinary language and ask what you have misunderstood. This gives the customer a chance to correct the story while the context is still fresh. Do not ask only whether they agree with an enthusiastic summary.
In your notes, distinguish a verbatim quote, an editorial summary and a claim that still needs checking. Record which customer representative can confirm a result and which material is confidential. A recording timestamp or a clear note beside a draft claim makes later review easier than searching an hour of conversation from the beginning.
When sending the draft for approval, show the headline, quotations and relevant context together. A customer may agree with each individual sentence while finding the headline broader than their experience supports. Resolve that difference before turning the story into a shorter testimonial or sales excerpt.
