Norman Chapter 1

• Two of the most important characteristics of good design:

  1. discoverability
  2. understanding
• Discoverability asks the questions:

  1. is it possible to figure out what actions are possible?
  2. where can I perform these actions?
  3. how do I perform these actions?
• understanding asks the questions:

  1. what does it all mean?
  2. how is the product supposed to be used?
  3. what do all the different controls and settings mean?
• All artificial things are designed, including the layout of furniture in a room, the paths through a garden or forest, and any electronic device
• Not all designed things involve a physical structure, including services, lectures, rules and procedures, and the organizational structure of businesses and government entities
• Industrial design refers to the professional service of creating and developing concepts and specifications that optimize the function, value, and appearance of products and systems for the mutual benefit of both user and manufacturer.
• Industrial designers emphasize form and material
• Interaction design focuses upon how people interact with technology
• The goal of interaction design is to enhance people's understanding of what can be done, what is happening, and what has just occurred
• Interaction design draws upon principles of psychology, design, art, and emotion to ensure a positive enjoyable experience
• Experience design refers to the practice of designing products, processes, services, events, and environments with a focus placed on the quality and enjoyment of the total experience
• Design is concerned with how things work, how they are controlled, and the nature of the interaction between people and technology
• It is the duty of machines and those who design them to understand people
• Reasons for deficiencies in human-machine interaction:

  1. Limitations of today's technology
  2. Self-imposed restrictions
  3. lack of understanding of the design principles necessary for effective human-machine interaction
• We have to accept human behavior the way it is, not the way wish it to be
• We must design our machines on the assumption that people will make errors
• Human centered design (HCD) is an approach that puts human needs, capabilities, and behavior first, then designs to accommodate those needs, capabilities, and ways of behaving
• Good design:

  • starts with an understanding of psychology and technology
  • requires good communication, especially from machine to person, indicating what actions are possible, what is happening, and what is about to happen
• Communication is especially important when things go wrong; designers need to focus their attention on the cases where things go wrong, not just on when things work as planned
• Human centered design is a design philosophy
• Human centered design starts with a good understanding of people and the needs that the design is intended to meet, which comes primarily from observation for people themselves are often unaware of their true needs and the difficulties they are encountering
• The HCD principle is to avoid specifying the problem as long as possible and instead iterate upon repeated approximations; this is done through rapid tests of ideas, in which the approach and the problem definition is modified after every test
• HCD is a philosophy and a set of procedures, whereas experience, industrial, and interaction design are areas of focus
• experience is critical; it determines how fondly people remember their interactions
• cognition and emotion are tightly intertwined, which means that designers must design with both in mind
• Discoverability results from appropriate application of five fundamental psychological concepts:

  1. affordances
  2. signifiers
  3. constraints
  4. mapping
  5. feedback
• the conceptual model of the system provides true understanding
• An affordance is the relationship between a physical object and any interacting agent, including people, animals, or even machines or robots
• An affordance is a relationship between the properties of an object and the capabilities of the agent that determines just how the object could possibly be used
• affords means "is for"; example: a chair affords comfort
• the presence of an affordance is jointly determined by the qualities of the object and the abilities of the agent that is interaction
• an affordance is a relationship, whether an affordance exists depends upon the properties of both the object and the agent
• An anti affordance is the prevention of an interaction
• To be effective, affordances and anti affordances have to be discoverable and perceivable
• if an affordance or anti affordance cannot be perceived , some means of signaling its presence is required (signifier)
• The notion of affordance and the insights it provides originated with JJ Gibson, a psychologist who provided many advances to our understanding of human perception
• Gibsonian psychology refers to an ecological approach to perception
• Affordance happens when physical objects conveyed important information about how people could interact with them
• Affordances exist even if they are not visible
• For designers, the visible affordances provide strong clues to the operation of things