Donald A. Norman
Business and industry:
- 'business and industry have learned that their products ought to be aesthetically pleasing. A large community of designers exists to help improve appearances. But appearances are only part of the story: usability and understandability are more important, for if a product can't be used easily and safely, how valuable is its attractiveness? Usable design and aesthetics should go hand in hand: aesthetics need not be sacrificed for usability, which can be designed in from the first conceptualisation of the product' (pg.vi).
Usable design: the next competitive frontier:
- 'modern industry must distinguish itself through its consideration of the needs of its customers' (pg.vi).
- 'designers know too much about their product to be objective judges: the features they have come to love and prefer ma not be understood or preferred by the future customers' (pg.vii).
CHAPTER 1:
The psychology of everyday things:
- 'the importance of visibility, appropriate clues, and feedback of one's actions. These principles constitute a form of psychology - the psychology of how people interact with things' (pg.9).
- how do people cope with the multiple interferences of everyday things? 'part of the answer lies in the way the mind works - in the psychology of human thought and cognition. Part lies in the information available from the appearance of the objects - the psychology of everyday things. And part comes from the ability of the designer to make the operation clear, to project a good image of the operation, and to take advantage of other things people might be expected to know. Here is where the designer's knowledge of the psychology of people coupled with the knowledge of how things work becomes crucial' (pg.12).
The paradox of technology:
- 'technology offers the potential to make life easier and more enjoyable; each new technology provides increased benefits. At the same time, added complexities arise to increase our difficulty and frustration. The development of technology tends to follow a U-shaped curve of complexity: starting high; dropping to a low, comfortable level; then climbing again' (pg.30).
- 'the same technology that simplifies life by providing more functions in each device also complicates life by making the device harder to learn, harder to use. This is the paradox of technology'.
- 'the paradox of technology should never be used as an excuse for poor design. The principles of good design can make complexity manageable' (pg.31).
CHAPTER 2:
The seven stages of action:
- 'the specific actions bridge the gap between what we would like to have done (our goal and intentions) and all possible physical actions'.
- 'forming the goal, forming the intention, specifying an action, executing the action, perceiving the state of the world, interpreting the state of the world, and evaluating the outcome' (pg.48).
The seven stages of action as design aids:
- 'visibility: by looking, the user can tell the state of the device and the alternatives for action'.
- 'a good conceptual model: the designer provides a good conceptual model for the user, with consistency in the presentation of operations and results and a coherent, consistent system image'.
- 'good mappings: it is possible to determine the relationships between actions and results, between the controls and their effects, and between the system state and what is visible'.
- 'feedback: the user receives full and continuous feedback about the result of actions' (pg.53).
CHAPTER 3:
Knowledge in the head and in the world:
- 'information is in the world: much of the information a person needs to do a task can reside in the world. Behaviour is determined by combining the information in the head (memory) with that of the world'.
- 'great precision is not required: precision, accuracy and completeness of knowledge are seldom required'.
- 'natural constraints are present: the world restricts the allowed behaviour'.
- 'cultural constraints are present: in addition to natural, physical constraints, society has evolved numerous artificial conventions that govern acceptable social behaviour. These cultural conventions have to be learned' (pg.55).
- 'people function through their use of two kinds of knowledge: knowledge of and knowledge how. Knowledge of - what psychologists call declarative knowledge - includes the knowledge of facts and rules. Knowledge how - what psychologists call procedural knowledge - is the knowledge that enables a person to perform an action. Procedural knowledge is largely subconscious' (pg.57-58).
CHAPTER FOUR:
Conscious and subconscious behaviour:
- 'much human behaviour is done subconsciously, without conscious awareness and not available to inspection. Subconscious thought matches patterns. It operates by finding the best possible match of one's past experience to the current one. It proceeds rapidly and automatically'.
- 'conscious thought is slow and laboured. Here is where we slowly ponder decisions, think through alternatives, compare different choices' (pg.125).
- 'both conscious and subconscious modes of thought are powerful and essential aspects of human life. Both can provide insightful leaps and creative moments. And both are subject to errors, misconceptions and failures' (pg.126).
- 'subconscious thought is one of the tools of the conscious mind, and the memory limitation can be overcome if only an appropriate organisational structure can be found' (pg.127).
Social pressure and mistakes:
- 'although it may not at first seem to be relevant in design, it [social pressure] has strong influence on everyday behaviour. In industrial settings social pressures can lead to misinterpretations and mistakes' (pg.129).
CHAPTER 6:
The natural evolution of design:
- 'much good design evolves: the design is tested, problem areas are discovered and modified, and then it is continually retested and re-modified until time, energy and resources run out. This natural design process is characteristic of products built by craftspeople. With handmade objects, each new object can be modified slightly from the previous one, eliminating small problems, making small improvements or testing new ideas. Over time, this process results in functional, aesthetically pleasing objects'.
- however, 'natural design does not work in every situation: there must be enough time for the process to be carried out, and the item must be simple. Modern designers are subject to many forces that do not allow for the slow, careful crafting of an object' (pg.142).
Putting aesthetics first:
- 'if everyday design were ruled by aesthetics, life might be more pleasing to the eye but less comfortable; if ruled by usability, it might be more comfortable but uglier' (pg.151).
Designers are not typical users:
- 'designers often think of themselves as typical users. After all, they are people too, and they are often users of their own designs. All of us develop an everyday psychology. As human beings, we have access to our conscious thoughts and beliefs but not our subconscious ones. Conscious thoughts are often rationalisations of behaviour, explanations after the fact. We tend to project our own rationalisations and beliefs onto the actions and beliefs of others. But the professional should be able to realise that human belief and behaviour are complex and that the individual is in no position to discover all the relevant factors. There is no substitute for interaction with and study of actual users of a proposed design' (pg.155).