5 Prototyping Design Concepts

What prototypes make possible

A Prototype is a tangible, partial version of a design idea that lets people experience and discuss the part being investigated. It might be a sketch, role-play, model, or interactive digital screen; it does not have to be a miniature finished product.

Prototypes help a team explore how an idea might work and learn from people’s responses before investing in a complete solution. They can also help collaborators from different disciplines, such as design, engineering, research, and operations, share an idea.

Choose a method for the question

Begin with the question, “What do we need to learn?” Choose the simplest method that lets people meaningfully respond. Different parts of one concept may call for different prototypes, and methods can be combined.

• Does the basic idea make sense? Use a sketch, storyboard, or concept card. For example, draw how a library pickup service might work from request to collection.

• Can people find their way through a sequence? Use paper screens, wireframes, or a clickable screen flow. For example, let someone try to reserve a book using rough screen layouts.

• How might an interaction feel? Use a role-play, scenario, or improvised service simulation. For example, act out a check-in conversation between a visitor and a staff member.

• Does an object fit or work physically? Use cardboard, foam, or another quick physical model. For example, make a rough handle to check grip and reach.

• Can a realistic digital interaction be used successfully? Use an interactive prototype or coded mock-up. For example, test whether people can complete a booking using realistic screens and controls.

Methods can work together: a storyboard might explain a service journey while a simple model helps test one physical touchpoint.

Choose an appropriate level of fidelity

Fidelity describes how closely a prototype represents the intended design. It can refer to appearance, content, interaction, or function, so a prototype can be detailed in one respect and rough in another.

• Low fidelity is quick, inexpensive, and deliberately incomplete. Sketches, paper interfaces, rough models, and role-play can help explore alternatives, test the overall concept, or find out whether a sequence is understandable.

• Medium fidelity adds structure or detail, such as clearer layouts, sample content, or linked screens. It can help examine information flow and key interactions without building the full solution.

• High fidelity closely resembles the intended experience in appearance or behavior. A polished clickable interface or a working model of a critical feature can help when realistic interactions, visual details, or technical constraints matter to the question.

Higher fidelity is not automatically better. Polished prototypes take more effort and can make an early idea seem more finished than it is. Start with a low-cost representation when the main uncertainty is about the concept or user need, and add detail only when it helps answer the next question. Even a realistic digital prototype is not a production-ready service.

Build, observe, and revise

Use a focused cycle to learn from a prototype and decide what to change.

1. Name the learning goal. Turn an uncertainty into a focused question, such as, “Can a first-time visitor find the correct appointment option?”

2. Select the method and fidelity. Include only enough detail for someone to experience the aspect being tested.

3. Make the prototype understandable. Explain what it represents and what is not yet functional. Do not present assumptions as settled facts.

4. Invite people to try it. Give them a realistic task or scenario. Observe what they do, where they pause, and what they misunderstand. Ask open questions about their experience rather than leading them toward a preferred answer.

5. Record what you learn and iterate. Note evidence, unexpected reactions, and unresolved questions. Revise the prototype, test a different version, or change the concept. Keep the prototype focused so the team can tell which design choices prompted different responses.

Apply the process to a service

A team exploring a neighborhood clinic’s appointment process might first sketch several possible ways to choose an appointment. After learning which structure people understand, the team could create linked screens to test navigation. A more realistic prototype might then help examine the wording and behavior of a particular step.

Each version is useful because it answers a different question, not simply because it is closer to a finished product. Choose a method according to what needs to be learned, use the lowest fidelity that can answer the question, and increase detail when realism matters to the next decision.