Interaction Design

Your constantly-updated definition of Interaction Design and collection of topical content and literature


What is Interaction Design?

Interaction Design (IxD) is the design of interactive products and services in which a designer’s focus goes beyond the item in development to include the way users will interact with it. Thus, close scrutiny of users’ needs, limitations and contexts, etc. empowers designers to customize output to suit precise demands.

What Designers Do – with the 5 Dimensions of IxD

For UX designers, “Interaction Design” is the axis on which our work revolves (i.e., the design of human interaction with digital products); however, the term also applies to understanding how people interact with non-digital products.

“Interaction Design is the creation of a dialogue between a person and a product, system, or service. This dialogue is both physical and emotional in nature and is manifested in the interplay between form, function, and technology as experienced over time.”

- John Kolko, Author of Thoughts on Interaction Design (2011)

Designers’ work in IxD involves five dimensions: words (1D), visual representations (2D), physical objects/space (3D), time (4D), and behavior (5D).

Learn more about the 5 factors of interaction design and the kind of work IxD involves.

IxD’s five dimensions were first defined by a professor at London’s Royal College of Art, Gillian Crampton Smith, and a senior interaction designer, Kevin Silver. The dimensions represent the aspects an interaction designer considers when designing interactions. Words (1D) encompass text, such as button labels, which help convey the right amount of information to users. Visual representations (2D) are graphical elements such as images, typography and icons that aid in user interaction. Physical objects/space (3D) involves the medium through which users interact with the product or service—for instance, a laptop via a mouse, or a mobile phone via fingers. Time (4D) relates to media that changes with time, such as animations, videos, and sounds. Behavior (5D) is concerned with how the previous four dimensions define the interactions a product affords—for instance, how users can perform actions on a website, or how users can operate a car. Behavior also refers to how the product reacts to the users’ inputs and provides feedback.

Interaction designers utilize all five dimensions to consider the interactions between a user and a product or service in a holistic way. Specifically, we use them to help envision the real-world demands of a usership in relation to a design not yet introduced. For example, designers of an app that must process data at high speed in order to find results inside a mass-transit system (a subway/metro) will face accommodating the constraints of underground commuters – cramped spaces, fast journeys, dead zones, etc.

Interaction Design is a Part of User Experience Design

The term “interaction design” is sometimes used interchangeably with “user experience design”. That’s understandable, considering interaction design is an essential part of UX design. Indeed, UX design entails shaping the experience of using a product, and a big part of that experience involves the needed interaction between the user and the product. However, UX design goes far beyond that. UX designers’ working world is concerned with the entire user journey, including aspects of branding, design, usability and function. Conversely, the central role of “interaction designers” targets the moment of use and how to improve the interactive experience. Thus, interaction design, or IxD, is pivotal in the realm of the user experience, since the moment of use is the acid test of a design, where the designer’s manipulation of the five dimensions must offer users a satisfactory—if not better—experience. If users find themselves hindered by impractical features, such as text-heavy notifications or overlong animations, are put off by the aesthetics, or the responsiveness of the design fails to match their needs in the context, the design will fail, regardless of the brand behind it. The IxD of a product reflects its absolute value.

Learn More about Interaction Design

Read’s questions to consider when designing for interaction here:

UX Matters has a great article by Kevin Silver on the 5 dimensions of interaction design – here:

You can learn much more about what interaction design is and how to design interactions in the Interaction Design Foundation’s online courses. Read more about the courses we offer – here:

Literature on Interaction Design

Here’s the entire UX literature on Interaction Design by the Interaction Design Foundation, collated in one place:

Featured article

What is Interaction Design?

What is Interaction Design?

Interaction design is an important component within the giant umbrella of user experience (UX) design. In this article, we’ll explain what interaction design is, some useful models of interaction design, as well as briefly describe what an interaction designer usually does.

A simple and useful understanding of interaction design

Interaction design can be understood in simple (but not simplified) terms: it is the design of the interaction between users and products. Most often when people talk about interaction design, the products tend to be software products like apps or websites. The goal of interaction design is to create products that enable the user to achieve their objective(s) in the best way possible.

If this definition sounds broad, that’s because the field is rather broad: the interaction between a user and a product often involves elements like aesthetics, motion, sound, space, and many more. And of course, each of these elements can involve even more specialised fields, like sound design for the crafting of sounds used in user interactions.

As you might already realise, there’s a huge overlap between interaction design and UX design. After all, UX design is about shaping the experience of using a product, and most part of that experience involves some interaction between the user and the product. But UX design is more than interaction design: it also involves user research (finding out who the users are in the first place), creating user personas (why, and under what conditions, would they use the product), performing user testing and usability testing, etc.

The 5 dimensions of interaction design

The 5 dimensions of interaction design(1) is a useful model to understand what interaction design involves. Gillian Crampton Smith, an interaction design academic, first introduced the concept of four dimensions of an interaction design language, to which Kevin Silver, senior interaction designer at IDEXX Laboratories, added the fifth.

1D: Words

Words—especially those used in interactions, like button labels—should be meaningful and simple to understand. They should communicate information to users, but not too much information to overwhelm the user.

2D: Visual representations

This concerns graphical elements like images, typography and icons that users interact with. These usually supplement the words used to communicate information to users.

3D: Physical objects or space

Through what physical objects do users interact with the product? A laptop, with a mouse or touchpad? Or a smartphone, with the user’s fingers? And within what kind of physical space does the user do so? For instance, is the user standing in a crowded train while using the app on a smartphone, or sitting on a desk in the office surfing the website? These all affect the interaction between the user and the product.

4D: Time

While this dimension sounds a little abstract, it mostly refers to media that changes with time (animation, videos, sounds). Motion and sounds play a crucial role in giving visual and audio feedback to users’ interactions. Also of concern is the amount of time a user spends interacting with the product: can users track their progress, or resume their interaction some time later?

5D: Behaviour

This includes the mechanism of a product: how do users perform actions on the website? How do users operate the product? In other words, it’s how the previous dimensions define the interactions of a product. It also includes the reactions—for instance emotional responses or feedback—of users and the product.

See how 5 dimensions of interaction design come together in the animation below:

Important questions interaction designers ask

How do interaction designers work with the 5 dimensions above to create meaningful interactions? To get an understanding of that, we can look at some important questions interaction designers ask when designing for users, as provided by

  • What can a user do with their mouse, finger, or stylus to directly interact with the interface? This helps us define the possible user interactions with the product.
  • What about the appearance (colour, shape, size, etc.) gives the user a clue about how it may function? This helps us give users clues about what behaviours are possible.
  • Do error messages provide a way for the user to correct the problem or explain why the error occurred? This lets us anticipate and mitigate errors.
  • What feedback does a user get once an action is performed? This allows us to ensure that the system provides feedback in a reasonable time after user actions.
  • Are the interface elements a reasonable size to interact with? Questions like this helps us think strategically about each element used in the product.
  • Are familiar or standard formats used? Standard elements and formats are used to simplify and enhance the learnability of a product.

So what do interaction designers do?

Well, it depends.

For instance, if the company is large enough and has huge resources, it might have separate jobs for UX designers and interaction designers. In a large design team, there might be a UX researcher, an information architect, an interaction designer, and a visual designer, for instance. But for smaller companies and teams, most of the UX design job might be done by 1-2 people, who might or might not have the title of “Interaction Designer”. In any case, here are some of the tasks interaction designers handle in their daily work:

Design strategy

This is concerned with what the goal(s) of a user are, and in turn what interactions are necessary to achieve these goals. Depending on the company, interaction designers might have to conduct user research to find out what the goals of the users are before creating a strategy that translates that into interactions.

Wireframes and prototypes

This again depends on the job description of the company, but most interaction designers are tasked to create wireframes that lay out the interactions in the product. Sometimes, interaction designers might also create interactive prototypes and/or high-fidelity prototypes that look exactly like the actual app or website.

Diving deeper into interaction design

If you’re interested to find out more about interaction design, you can read Interaction Design – brief intro by Jonas Lowgren, which is part of our Encyclopedia of Human-Computer Interaction. It provides an authoritative introduction to the field, as well as other references where you can learn more.

References & Where to Learn More

Course: Interaction Design for Usability -

Further literature and resources on interaction design -

5 dimensions of interaction design -

Questions to consider when designing for interaction -

Hero Image: Author/Copyright holder: Copyright terms and licence: CC0

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Learn more about Interaction Design

Take a deep dive into Interaction Design with our course Psychology of Interaction Design: The Ultimate Guide.

A deep understanding of human psychology is essential for all designers when creating a user-centered product with great user experience. While many individual differences will never cease to exist between users, we are united by our shared psychology; the constraints and abilities of the human mind are much the same for all of us. Developing an understanding of these cognitive limitations and capabilities is the key to interaction design and a great user experience. Without an awareness of how we interact with things in the real and virtual worlds, you’ll find that your designs will fall short of their potential.

This course will equip you with the knowledge to relate to your users psychologically, thus allowing you to create stand-out products. Through learning about different aspects of human cognition—and how they relate to interaction design—you will find yourself much better equipped to put yourself in your users’ shoes, shifting their thoughts to the forefront and keeping a firm hold of them there when designing your next creation.

All literature

Human Computer Interaction - brief intro

Ch 2: Human Computer Interaction - brief intro

Human-computer interaction (HCI) is an area of research and practice that emerged in the early 1980s, initially as a specialty area in computer science embracing cognitive science and human factors engineering. HCI has expanded rapidly and steadily for three decades, attracting professionals from many other disciplines and incorporating diverse ...

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What is Interaction Design?

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Interaction design is an important component within the giant umbrella of user experience (UX) design. In this article, we’ll explain what interaction design is, some useful models of interaction design, as well as briefly describe what an interaction designer usually does. A simple and useful understanding of interaction designInteraction de...

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Interaction Design - brief intro

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Industrial Design

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Interaction Design Patterns

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Tactile Interaction

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