What is interaction design?
Glossary · By Utkarsh Dhairya Panwar · Updated
Interaction design (IxD) is the design of how a product behaves when someone uses it: what they can do, what happens when they do it, and how it shows the result and the next step. UI design decides how a screen looks. Interaction design decides how it responds.
The questions an interaction designer answers
- What can I do here? (affordances and signifiers: does it look pressable, draggable, editable)
- What happens when I do it? (the response, and how fast it comes)
- Did it work? (feedback: a state change, a message, a sound, a movement)
- What if it didn't? (errors, recovery, undo, retry)
- What can I do next? (the next step, made obvious)
A static mockup only answers the first question, which is why this work lives in prototypes, state diagrams and written rules as much as in Figma frames.
A product example: when a payment fails
At FamPay, a payments app for teenagers in India, I worked on what the iOS app does when a payment doesn't go through. A timeout, a bank decline and a retry had been sharing one generic failure message, even though they're different situations.
| Situation | What the person needs to know | What they can do next |
|---|---|---|
| Timeout | The outcome isn't known yet, and money may or may not have moved | Wait for a final status, without paying twice |
| Bank decline | The bank said no, and no money moved | Try another method, or retry later |
| Retry | What will happen this time, and that the first attempt won't also go through | Confirm the retry with that reassurance in view |
Giving each situation its own state, with one error pattern across the app so people learn it once, is the plainest example of interaction design I have. The full story and test results are in my guide to payment failure UX.
A playful example: interfaces you touch with your hands
Outside client work I build small interactive pieces with AI coding tools, partly to practise this. Mitti, at the top of the page, is a pottery wheel you shape with webcam hand gestures. Type Piano turns typing into posters. Neither has buttons to fall back on, so a gesture without instant, readable feedback makes the whole piece stop making sense.
Type Piano: each key press lands on the poster immediately, so you always know which key did what.
Common misconceptions
- "It means animation." Motion is one tool for feedback. A well-written error message is interaction design too.
- "It happens after the visual design." States and rules should be decided before screens are polished, or engineers end up guessing them.
| Discipline | Main question |
|---|---|
| Interaction design | How does it respond, and what can I do next? |
| UI design | How does it look: layout, type, colour, components? |
| UX design | Does the whole experience solve the problem? |
| Information architecture | Where does everything live, and what is it called? |
Questions people ask
What are the principles of interaction design?
The usual set is visibility, feedback, constraints, consistency and clear affordances, mostly from Don Norman's work. In practice: show what's possible, respond to every action, and make mistakes recoverable.
Does an interaction designer need to code?
No, but they have to show behaviour as well as screens. I build working prototypes with AI coding tools when timing or gestures matter, and use Figma prototypes for most flows.
What does an interaction designer deliver?
User flows, interactive prototypes, state definitions for each component (loading, empty, error, success) and written rules engineers can build from.
Sources
- 10 Usability Heuristics for User Interface Design, Nielsen Norman Group
- Signifiers, not affordances, Don Norman, JND.org
- What is Interaction Design (IxD)?, Interaction Design Foundation
Working on this?
Tell me what you're building and where it's stuck: book a 30-minute call, email work@utkarshdesign.com or send a brief.