# The Design of Everyday Things

__"Design is concerned with how things work, how they are controlled, and the nature of the interaction between people and technology"__

## Chapter 1: The Psychopathology of Everyday Things

The key question is: why are everyday things sometimes so hard to use? The author says that the knowledge of how to operate machines should come from the design of the object itself. For example if you have to place a "push" sign onto a door, the design is not good.

The problem often lies with the engineers. Engineers are trained to think logically so they design products with their logical thinking. But the average human is not that logical. We tend to design things for how we would like people to be, not for the way they really are. Therefore one has to deep into human psychology.

__"Two of the most important characteristics of good design are _discoverability_ and _understanding_. Discoverability: Is it possible to even figure out, what actions are possible and where and how to perform them? Understanding: What does it all mean? How is the product supposed to be used? What do all the different controls and settings mean?"__

### The Complexity of Modern Devices (TODO)

### Human-Centered Design (TODO)

### Fundamental Principles of Interaction

__"Discoverability results from appropriate application of five fundamental psychological concepts [...]: _affordances_, _signifiers_, _constraints_, _mappings_ and _feedback_. But there is a sixth principle, perhaps most important of all: the _conceptual model_ of the system."__

#### Affordances

__"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".__

Glass affords transparency and therefore seeing through for most people. For blind people glass does not afford seeing through. So have in mind that affordances are not properties of the object! They just describe what actions are possible for a certain agent

#### Signifiers

__"_Signifiers_ communicate where the action should take place"__

Good design requires communication about how to use an object. Designers cannot communicate directly with the user and therefore must implement the communication within the design. That is where signifiers come in place. 

A metal plate directly plated on a door signals pushing, whereas a knob signals pulling.

#### Constraints

<!-- I did not read that yet -->

#### Mappings

__"Mapping is an important concept in the design and layout of controls and displays. When the mapping uses spatial correspondence between the layout of the controls and the devices being controlled, it is easy to determine how to use them."__

__"Natural mapping, by which I mean taking advantage of spatial analogies, leads to immediate understanding. For example, to move an object up, move the control up."__

Some other analogies are also possible: a movement up can also mean that something increases in amount. Therefore it is appropriate to use vertical movement to represent intensity or amount.

#### Feedback

must be
1. immediate
2. put in right amount
3. prioritized

__"Feedback - communicating the results of an action"__

A user has to know whether a system is working on a request or not. Even such trivial things like lifting a glass need feedback. Where is the glass? If the aim is not right, the content can be spilled. Do I use the right force? If grabbed to softly, the glass will fall, grab it too tight and it will break. 

__"Feedback must be immediate"__

If the delay is too long, users tend to loose interest and/or give up although the system is working on the request.

__"Too much feedback can be even more annoying than too little"__

An example for excessive feedback is the backseat driver. He/she can become so annoying that the driver can be distracted which is a real danger.

__"Feedback has to be planned. All actions need to be confirmed, but in a manner that is unobtrusive. Feedback must also be prioritized"__

Example for prioritizing: Hospitals. If every alert sound would be the same doctors were not be able to tell the urgent cases from the minor ones. Even worse: they would start to ignore all the alarms.

#### Conceptual models

__"It is the conceptual model that provides true understanding."__

__"A conceptual model is an explanation, usually highly simplified, of how something works"__

__"Simplified models are valuable only as long as the assumptions that support them hold true."__

__"Conceptual models are valuable in providing understanding, in predicting how things will behave, and in figuring out what to do when things do not go as planned. A good conceptual model allows us to predict the effects of our actions."__

### The System Image (TODO)

### The Paradox of Technology (TODO)

### The Design Challenge (TODO)

## Chapter 2: The psychology of Everyday Actions (TODO)

## Chapter 3: Knowledge in the Head and in the World (TODO)

## Chapter 4: Knowing What to Do: Constraints (TODO)

## Chapter 5: Human Error? No, Bad Design (TODO)

## Chapter 6 Design Thinking (TODO)

## Chapter 7: Design in the World of Business (TODO)