Product Sense: Create a Toothbrush for a Chosen User Group and Prioritize Its Features

You are asked to create a new toothbrush. The interviewer sets no other constraints: you choose who the product is for, which problem it solves and what the first version includes. Take the design from a goal to a prioritized set of features, and explain how you would know the product is succeeding. ```hint Start from a sharp problem Most people can already clean their teeth with an ordinary brush. Look for a group whose brushing goes wrong in a specific, observable way, and let that problem decide the features. ``` ### Clarifying Questions - Is there a target user in mind, such as young children, adults, older adults with a weak grip, or people with braces, or may I choose? - Should it be a manual brush, a powered brush, or a connected brush that works with a phone app? - What is the business goal: entering a new segment, a premium product with high margins, or a sustainability-led line? - Is there a target price range or a launch market? ### What a Strong Answer Covers - A stated goal for the product and a reasoned choice of one user segment over the alternatives. - Pain points across the whole journey: choosing and buying, brushing, knowing whether brushing worked, replacing heads, and disposal. - Several solutions tied to those pain points, prioritized by impact, effort and confidence into a first version and later additions. - Success metrics suited to a physical product (brushing habit, oral-health outcome, repeat purchase) with guardrails on safety, cost and privacy. - Risks and trade-offs, such as manual versus powered and screen-free versus app-connected. ### Follow-up Questions - How would you test demand and the core feature before committing to manufacturing? - If the brush connects to an app, what data would you collect, and how would you protect it? - How would your design change for a market where most buyers spend very little on a toothbrush?