The fundamental principles of Interaction Design (IxD) that enhance user-product communication

The fundamental principles of Interaction Design (IxD) that enhance user-product communication

What is interaction design?

Before I dive straight into today’s topic for discussion, let’s first take a short tour of the foundation of the matter itself. In other words, let me first give you a basic introduction to interaction design to set the ball rolling.

According to its definition on Wikipedia, interaction design or IxD, as it is also known by, is "the practice of designing interactive digital products, environments, systems, and services" that are used by us in our everyday lives.

Now, if you look at it purely through a tunnel-visioned perspective it is just that - a collective of digital experiences. Expand your focus, however, and you’ll learn that IxD is not just designing these digital experiences, but also instrumental in facilitating an ‘interaction’ with these products, which just so happens to be non-digital in nature.

In simplest of terms, interaction design is primarily the study of human behavior displayed when they interact with these digital devices and based on the analysis, forming an idea of the experience as it should be. As such, the related field of study that goes by the name of human-computer interaction (HCI) also finds itself being commonly drawn into the discussion.

Another subject that becomes an important part of the discussion is the area of design itself. As I already mentioned, IxD focuses more on the designing of interactive products as they are supposed to be, while learning heavily from users to work on improvements along the way.

To that end, certain principles have been propounded as the basic foundation that would are necessary for effective interaction design. Most notable among the contributors is American cognitive scientist and usability engineer Donald Arthur Norman, who also happens to be the director of the Design Lab at the University of California in San Diego, California.

In fact, Don Norman’s book ‘The Design of Everyday Things,’ which was originally published way back in 1988 under the title ‘The Psychology of Everyday Things’ became a gold standard in design practice. Stressing on the scope of design as one riding on the needs of the users, he iconized the term user-centered design, which can be considered as a precursor to the principles that we are going to discuss in details.

Don Norman’s Design of Everyday Things ascribes design as an aspect that’s based on human needsSource: medium com

What are the principles of interaction design?

The present day world is literally abuzz with design principles presented by various experts in the field. But, since we are in so much awe of the man who introduced the world to HCI, it’s only befitting that we go by the six principles of design that Don Norman himself advocated.

These principles find resonance in their application to not just the most basic of instruments or appliances but even the latest digital channels like websites, web applications, mobile applications, portable devices, IoT devices and wearable technology. And here they are, in what we believe should be in an order according to their importance.

1. Visibility

Visibility in interaction design is easily the most fundamental principle of design. Quite simply put, if there is no visible piece of action or function to act as a cue, users will be unsure of what their next step of action should be due to the obvious absence of information. This scenario can apply to anything from a basic object to the most complex of digital interfaces.

Visible elements offer users obvious prompts to make their next move, thus establishing interaction

Availability of visible actions that are obvious enough to prompt users into taking their next step are just as crucial as the lack of it in understanding user behavior. A series of such steps indicate a clear interaction between the user and the design interface. Effective design is all about identifying what users need and offering exactly that to them.

Design of good messaging experience on Facebook through quick response action buttonsSource:

The much discussed topic of hamburger menu vs tab bar menu has opened up conflicting opinions on the practical advantages of these navigation bars. While the effectiveness of an interface rests on the principle of visibility, the fact also remains that design elements cannot be a universal pattern.

For example, while hamburger menus can be a good navigation choice when the interface/page focuses heavily on visual design where related information become secondary and can therefore be tucked away within a hamburger menu. The same cannot be said, however, about interfaces that require quick action response from users, in which case tab bar navigation works best.

Hamburger menu vs tab bar menu as navigation option on a mobile deviceSource:

Of course, the balancing act of moving certain menu items to the hamburger menu and keeping the immediately necessary items in the prominently visible tab bar is all about prioritizing which items are most important. And the act finds advocates in those who feel that hamburger menu and tab bar can go together for a better spatial arrangement, especially on mobile devices.

Accessible design is good design

– Steven Anthony Ballmer, American businessman, investor & former CEO of Microsoft

2. Feedback

Imagine yourself as a user of an app or an interface where you find yourself waiting for a response after clicking a button without receiving one. Yes, we’ve all been there and I’m sure most of us would relate to this familiar scenario.

Even for a layman it’s a simple fact that when you click a button to initiate an action, there would usually be a consequence to it. Like when you click the “subscribe” button on a webpage and receive a prompt “thank you” message.

Feedback in any digital interface is a crucial design element to let users understand if there was consequence to their actionSource:

Feedback is an important principle of design that’s applicable to all digital channels, including mobile phones, computers, kiosks and wearable devices. It’s that vital piece of interaction without which users would be left wondering what kind of action they initiated and what the consequence of that action was.

Now, the feedback itself could be presented in varying forms, including pop-up messages, animated graphics (visual), even audio messages and at times a combination of all. Ever paid attention to those accessible pedestrian signals (APS) or audible beaconing that you use everyday on your walk to office? Well, that’s a device designed specifically for visually impaired people to be guided through audible signals (instructions).

Of course, there’s also that part where feedback splits up into two basic loops known in the world of design as positive feedback and negative feedback. These two processes in the feedback loop go on to determine the rise or fall in user reaction to a digital experience, where an increase in reaction would be a manifestation of satisfaction while decrease in reaction would be the result of a dissatisfying experience. Click here to read more on feedback designing in digital products.

Alt Text: Questions vital to an effective feedback design Source:

3. Constraints

Contrary to its meaning and experience in real life, constraints in design actually happen to provide convenience by removing or restricting the scope of interaction between an interface and its user. This is an act of simplifying a process that could otherwise be complicated for users through way too many interaction elements.

No complicated and multiple actions, no confusion in the minds of the users what the interface allows them to do. The idea is to rest the focus on the primary personality of the interface by doing away with unnecessary elements that could take away the focus from its real value.

In the world of design, too many elements can be an overcomplicating distraction that could sabotage an an app, a digital product or a website even before it could take off. Another reason to limit interaction is to narrow the chances of anything going wrong (read errors) if a user does things on a digital interface that they are not supposed to.

Constraints in interaction design are meant to reduce confusion and the chances of errorsSource:

As you can see in the above image that a lot of the functions are greyed out, thereby rendering those functions unachievable for a user. This restriction of functions to just a few important and simple ones becomes imperative in interaction design to cut down the possibility of confusion and consequently errors.

The following principles are fundamental to the design and implementation of effective interfaces. They are applicable for web, mobile devices, wearables, and IoT devices.

4. Mapping

In simplest terms, mapping can be defined as the easily decipherable relationship between the controls on an interface and their effect. In other words, the layout and design specification that go on to establish connection between the controls and their functions, which ideally should be clear and simple enough for users to follow through without confusion.

But, as if ignoring this very principle are designs with poor mapping out there that simply don’t make sense at all. I mean, how difficult is it to get it right? One would understand in complex design scenarios the usage of labels so users can understand their functions.

Poor mapping as represented by the mismatched arrangement of knobs in a gas cooktopSource:

But when you look at the example of a poorly mapped kitchen cooktop, which is by the way is an overused example, you’ll see what I mean. In the image above, the displacement of the knobs on the gas cooktop don’t correspond to the arrangement of the burners. This creates a state of confusion in users that could have been avoided had the knobs been arranged in the same pattern as the burners.

Complex mapping on PS4 controller for one of the games developed for the consoleSource:

In contrast to that is something known as natural mapping or good mapping, in which the spatial layout and arrangement of the controls and their functions can be naturally established without the need for too much information.

This can be seen in the case of the Sony PS4 controller where the controls are intuitive enough for players to figure out what the functions are through what is known in game design as logic mapping even though it’s really complex mapping in design. Of course, the functions may vary based on specific game control configurations.

5. Consistency

One of the most important design principles that improves the experience of interaction between a product and a user is well-rounded consistency. For if design elements are not consistent throughout your product in aspect and function, it will reduce the smooth flow of action through inconsistent and thus confusing elements in design.

In design terms, consistency has been defined as similar operations with similar elements to achieve similar tasks. Pretty simple and straightforward, huh? But, that’s just what it’s all about. It should make usability easier, it should make learning simpler and it should render functionality intuitive. Click here to read more on consistency as a design principle.

Classic example of design consistency is the set of controls on a cassette recordeSource:

Examples of consistency can literally be found in every aspect of interaction between humans and a product, digital and non-digital. A classic interaction design example of consistency, as shown in the image above, is the assortment of controls on a cassette recorder that performs exactly the same tasks as they interpret, both in visual and interactive aspects. 

Consistency is crucial in design and if you work in an interaction design company, the sooner you warm up to that principle, the easier it will be for you to create effective designs.

6. Affordance

Affordance is the design principle that makes it clear for a user how an object / product / digital interface should be used. Oh, and one more thing. It should be self-explanatory, meaning the product should possess elements that would afford its use without any confusion.

Don Norman broke down this principle in simple terms by saying that affordance in design loosely translates to offering a clue to the users. And when the clues are clear and obvious enough for users to understand, the interactiveness of a product can be declared to be effective.

Graphical representation of affordance in electrical switchesSource:

Suffice to say, affordance has been a principle that was simple to follow through before the dawn of the digital age. Information entrapped in a digital interface can be somewhat like the switchboard of a telephone operator - if you don’t know what you are doing, you can easily get lost.

As such, if you’re an interaction designer, one of your priorities should be to enable users to execute tasks on your product/interface based purely on the cognizable information it affords them. As statistics would show, good affordances go on to increase interest and response in users, while poor affordances have led to poor response and ultimately disapproval.

Of course, this is the digital age and the possibilities are endless, as has been seen over the years with several groundbreaking innovations. That’s why breaking down the concept of affordance in a paragraph isn’t just right nor is it possible without diving further into subtopics like the types of digital affordance that affect user experience (UX).

What is bad interaction design?

At this stage you should be able to tell what the definition of bad interaction design is and it’s quite simple. Any design, including on an actual physical product and a digital interface, that fails to establish smooth interaction between it and the user is an example of bad interaction design. We’re talking about interactive products here and the whole foundation of success rests on good solid user experience.

The principles that we have explained here are the key to creating effective interaction design because each of them is aimed at putting the focus on usability to boost user interactivity and improve human experience. After all, if users are not to achieve their goals without confusion and obstacles, what good did all your hours in the design lab do?


These design principles, as we said before, are applicable for any product, digital or non-digital, that humans will interact with in some way. It doesn’t matter whether you design a sports equipment or a mobile application. The goal will always be to improve communication between products and their users.

At 0707, our approach to design is fastidiously human-centric, which is why we take great pains to conduct in-depth research before we begin a project to make optimal impact with the designs we create. If you have a product or design idea and you’re looking for the right agency to bring it to life in the most impactful manner, reach out to us with confidence.

0 Claps

Recent Insights