Duane Bray: three categories of interaction design
- screen-based experiences: pixel-based experiences
- interactive products: if no screen, relies on ambient feedback, using light, sound, or movement
- services: blurrs the boundaries between interaction design and organizational psychology

Prototypes are representations of a design made before final artifacts exist... created to inform both design process and design decisions.. range from sketchess and different kinds of models at various levels - "look like," "behaves like," "works like".

Experience Prototyping: Marion Buchenau and Jane Fulton Suri
three types of prototyping techniques:
- to understand existing user experiences and context
- to explore and evaluate design ideas
- to communicate ideas to an audience

Broader definition of interactive design: the design of everything that is both digital and interactive. It includes everyone who has the knowledge and tools that allow them to "create or contrive for a particular purpose or effect" in this digital context.

... the aesthetics, subjective and qualitative values, and human factors.

Narrow definition of interaction design: the design of the subjective and qualitative aspects of everything that is both digital and interactive, creating designs that are useful, desirable, and accessible... the first concern of the designer is the values of the people who will use the design ...

A hierarchy of complexity

... in response to new kinds of constraints, but design problems are changing all the time.

Designers are both enabled and controlled by the constraints that they learn about and come to understand; they are fluent with their tacit knowledge, in their own media, and in the contexts that they are familiar with and understand. This makes it difficult to develop a new design discipline ...

Good design comes from the successful synthesis of a solution that recognizes all the relevant constraints, and the nature of the constraints defines the difference between design disciplines.

People and prototypes

To "understand people and use prototypes for speed" is a good pragmatic summary of a way of answering a "how?" question, but it does not answer questions of what, why, or where.

"... would start from the needs and desires of the people who use a product or service..." - Bill Moggridge, 1980s on interaction design.

"... where one could design behaviors, animations, and sounds as well as shapes. This would be the equivalent of industrial design but in software rather than three-dimensional objects. Like industrial design, the discipline would be concerned with subjective and qualitative values ..."

"... prototyped. This approach tended to generate incremental improvements to the designs but did not encourage more radical innovation. I felt that there was an opportunity to create a new design discipline, dedicated to creating imaginative and attractive solutions in a virtual world ..."

"There were people with computer science backgrounds who were writing code and had a technical and performance-based vision of the design requirements. There were also human factors specialists, who had backgrounds in psychology and had been educated to evaluate and test designs that were ..."

...
- intuitive interaction
- quality of interaction: relating what we see to what we hear or feel