About Interaction design (IxD)
Interaction design (IxD) is “the practice of designing interactive digital products, environments, systems, and services.” Like many other design fields Interaction Design also has an interest in form but its main focus is on behaviour. What clearly marks Interaction design as a design field as opposed to a science or engineering field is that it is synthesis and imagining things as they might be, more so than focusing on how things are.
Interaction design is heavily focused on satisfying the needs and desires of the people who will use the product. Where other disciplines like software engineering have a heavy focus on designing for technical stakeholders of a project. ..
The term interaction design was first coined by Bill Moggridge and Bill Verplank in the mid 1980s. It would be another 10 years before other designers rediscovered the term and started using it. To Verplank, it was an adaptation of the computer science term user interface design to the industrial design profession. To Moggridge, it was an improvement over soft-face, which he had coined in 1984 to refer to the application of industrial design to products containing software (Moggridge 2006).
In 1990, Gillian Crampton-Smith established an interaction design MA at the Royal College of Art (RCA) in London (originally entitled “computer-related design” and now known as Design Interactions). In 2001, she helped found the Interaction Design Institute Ivrea, a small institute in Northern Italy dedicated solely to interaction design; the institute moved to Milan in October 2005 and merged courses with Domus Academy. In 2007, some of the people originally involved with IDII have now set up the Copenhagen Institute of Interaction Design (CIID).
Today, interaction design is taught in many schools worldwide.
 Goal-oriented design
Goal-oriented design (or Goal-Directed™ design) “is concerned most significantly with satisfying the needs and desires of the people who will interact with a product or service.”
Alan Cooper argues in The Inmates Are Running The Asylum that we need to take a new approach to how interactive software based problems are solved. The problems faced with designing computer based interfaces are fundamentally different to the challenges we face when designing interfaces for products that do not include software (e.g. hammers). Alan introduces the concept of cognitive friction, whereby we treat things as human when they are significantly complex enough, we cannot always understand how they behave, and computer interfaces are sufficiently complex as to be treated this way.
It is argued that we must truly understand the goals of a user (both personal and objective) in order to solve the problem in the best way possible and that the current approach is much oriented towards solving individual problems from the perspective of a business or other interested parties.
Goal-oriented design as explained in The Inmates Are Running The Asylum advocates for the use of personas, which are created after interviewing a significant number of users.
The aim of a persona is to “Develop a precise description of our user and what he wishes to accomplish.” The best method as described within The Inmates Are Running The Asylum is to construct fabricated users with names and back stories who represent real users of a given product. These users are not as much a fabrication as a byproduct of the investigation process. The reason for constructing back stories for a persona is to make them believable, such that they can be treated as real people and their needs can be argued for. Personas also help eliminate idiosyncrasies that may be attributed to a given individual.
 Cognitive dimensions
The cognitive dimensions framework provides a specialized vocabulary to evaluate and modify particular design solutions. Cognitive dimensions are designed as a lightweight approach to analysis of a design quality, rather than an in-depth, detailed description. They provide a common vocabulary for discussing many factors in notation, UI or programming language design.
Dimensions provide high-level descriptions of the interface and how the user interacts with it such as consistency, error-proneness, hard mental operations, viscosity or premature commitment. These concepts aid in the creation of new designs from existing ones through design manoeuvres that alter the position of the design within a particular dimension.
 Affective interaction design
Throughout the process of interaction design, designers must be aware of key aspects in their designs that influence emotional responses in target users. The need for products to convey positive emotions and avoid negative ones is critical to product success. These aspects include positive, negative, motivational, learning, creative, social and persuasive influences to name a few. One method that can help convey such aspects is the use of expressive interfaces. In software, for example, the use of dynamic icons, animations and sound can help communicate a state of operation, creating a sense of interactivity and feedback. Interface aspects such as fonts, color pallet, and graphical layouts can also influence an interface’s perceived effectiveness. Studies have shown that affective aspects can affect a user’s perception of usability.
Emotional and pleasure theories exist to explain people’s responses to the use of interactive products. These include Don Norman‘s emotional design model, Patrick Jordan’s pleasure model, and McCarthy and Wright’s Technology as Experience framework.
 Related disciplines
- Industrial design
- The core principles of industrial design overlap with those of interaction design. Industrial designers use their knowledge of physical form, color, aesthetics, human perception and desire, usability to create a fit of an object with the person using it.
- Human factors and ergonomics
- Certain basic principles of ergonomics provide grounding for interaction design. These include anthropometry, biomechanics, kinesiology, physiology and psychology as they relate to human behavior in the built environment.
- Cognitive psychology
- Certain basic principles of cognitive psychology provide grounding for interaction design. These include mental models, mapping, interface metaphors, and affordances. Many of these are laid out in Donald Norman‘s influential book The Design of Everyday Things.
- Human–computer interaction
- Academic research in human–computer interaction (HCI) includes methods for describing and testing the usability of interacting with an interface, such as cognitive dimensions and the cognitive walkthrough.
- Design research
- Interaction designers are typically informed through iterative cycles of user research. User research is used to identify the needs, motivations and behaviour of end users. They design with an emphasis on user goals and experience, and evaluate designs in terms of usability and affective influence.
- As interaction designers increasingly deal with ubiquitous computing and urban computing, the architects’ ability to make, place, and create context becomes a point of contact between the disciplines.
- User interface design
- Like user interface design and experience design, interaction design is often associated with the design of system interfaces in a variety of media but concentrates on the aspects of the interface that define and present its behavior over time, with a focus on developing the system to respond to the user’s experience and not the other way around.