The customer interview starts with “Tell me about the last time”

A maker plans to sell a bag that keeps groceries upright on the bus. A friend says it sounds useful. That answer is easy to give and hard to act on. A better opening is to ask someone to describe their last grocery trip. The walk, the transfer and the things they already carry can tell you where a new bag would have to fit.

Ask for a recent example

The U.K. Government Digital Service’s interview guide recommends open, neutral questions and concrete examples. In the bag example, start with “Tell me about the last time you brought groceries home without a car.” Follow with “What did you carry them in?” or “What happened when you changed buses?” These questions make room for a participant who found the trip easy and for someone who avoided buying fragile items altogether.

Give the participant time to finish. Ask what they did next and what made them choose it. If they say their usual bag “was annoying,” ask for the moment it caused trouble. You might learn that the problem was getting a free hand for a bus pass. A stronger base in the bag would solve a different problem.

Recruit people who have different reasons for their choices

Speak with people who take different routes, shop for different quantities or use different ways to carry things. Include people who already use alternatives and people who sometimes avoid the task. The point of a small round is to learn where situations differ and what possibilities are worth exploring. Record how you found participants so you know what the interviews cover.

Before the interview, explain what you are doing and ask about recording or taking notes. Keep only what you need to understand the experience. If someone shows a receipt or an order screen, the sequence may be useful even when the names and payment details are irrelevant.

Separate observations from ideas

Write down observations such as “two participants put eggs in a separate backpack.” Keep interpretations, such as “they may need a stable compartment,” in a separate note. The government service manual recommends sorting observations into themes and checking what those themes suggest doing next.

Pick one claim that you can test, such as whether someone can reach a bus pass while carrying the bag. Observe people trying the task with a prototype. An interview can show why a workaround exists. A small practical test can show whether the proposed design fits that moment.

• Ask for a particular day, task and sequence.
• Ask what the person already does to work around difficulty.
• Turn a repeated observation into a testable question.