Notes for Donald A. Norman The Design of Everyday Things
Key concepts: affordance, connectionism, design model, forcing functions, mapping, paradox of technology, power of constraints, stickiness of memory, taught helplessness, user's model.
Designer versus user model. Compare knowledge in the world to explicit versus implicit knowledge. Also consider 'stickiness' of memory when what is being learned relates or does not relate to the overall context of activities of which the learning is a part. Recall von Neumann's discussions about error tolerance of natural and artificial automata. Interesting categorization of slips. Suggests the ideal computer is invisible. Heim would argue strongly against this equivocating the computer as an ordinary tool. Norman's recommendation of designing software such that the computer disappears and the task is foregrounded allows concealing of enframing. “A worn sock is better than a mended one; not so with metaphysics.” Reaches similar conclusions as Heim but not at the same depth of ontological analysis.
Related theorists: Heim, Ong, von Neumann.
PREFACE TO THE 2002 EDITION
Would we dare apply Normans arguments to the creation of texts beyond his own self criticism of choice of titles; clearly yes, for that is the impetus of Barker task-oriented software documentation.
(vii) Far too many items in the world are designed, constructed, and foisted upon us with no understanding - or even care - for how we will use them. Calling something a “Norman door” is recognition of the lack of attention paid by the maker to the user, which is precisely my message.
This seems like a generalization designed to suit his purpose; are the majority of automobile accidents really the result of poor design: the admission, then, is that we routinely engage in risky behavior due to the poor designs in our environment that we cannot really avoid.
(viii) The problems sound trivial, but they can mean the difference between pleasure and frustration. The same principles that make these simple things word well or poorly apply to more complex operations, including ones in which human lives are at stake. Most accidents are attributed to human error, but in almost all cases the human error was the direct result of poor design.
The Hidden Frustrations of Everyday Things
The Book Title: A Lesson in Design
(x)
I talked with book buyers and clerks. My editor was correct: I needed
to change the word “psychology” to “design.” In titling my
book, I had been guilty of the same shortsightedness that leads to
all those unusable everyday things!
Lessons from DOET
(x) the
appearance of the device must provide the critical clues required for
its proper operation - knowledge has to be both in the head and in
the world.
(xi) The device must explain itself. Even the location
and operation of the controls require a conceptual model - an obvious
and natural relationship between their location and the operation
they control so you always known which control does what (in the book
I call this a “natural mapping”).
(xiv) Appropriate,
human-centered design requires that all the considerations be
addressed from the very beginning, with each of the relevant design
disciplines working together as a team.
Technology Changes Rapidly; People Change Slowly
(xiv)
in selecting examples, I deliberately kept away from high technology,
looking instead at everyday things, things that have been around a
while. High technology changes rapidly, but everyday life changes
slowly.
(xv) Each time a new technology comes along, new designers
make the same horrible mistakes as their predecessors. Technologists
are not noted for learning from the errors of the past. They look
forward, not behind, so they repeat the same problems over and over
again.
PREFACE
(xvii) Humans do
not always err. But they do when the things they use are badly
conceived and designed. Nonetheless, we still see human error blamed
for all that befalls society.
Acknowledgments
(xix) A
major argument in POET is that much of our everyday knowledge resides
in the world, not in the head. . . . People certainly do rely upon
the placement and location of objects, upon written texts, upon the
information contained within other people, upon the artifacts of
society, and upon the information transmitted within and by a
culture. There certainly is a lot of information out there in the
world, not in the head.
CHAPTER ONE
THE PSYCHOPATHOLOGY OF EVERYDAY THINGS
You
Would Need an Engineering Degree to Figure This Out
(2)(figure
1.1) Carelman's
Coffeepot for Masochists.
The French artist Jacques Carelman in his series of books Catalogue
d'objets introuvables (Catalong of unfindable objects)
provides
delightful examples of everyday things that are deliberately
unworkable, outrageous or otherwise ill-formed.
The
Frustrations of Everyday Life
(4)
The correct parts must be visible, and they must convey the correct
message. With doors that push, the designer must provide signals that
naturally indicate where to push. . . . The vertical plate and
supporting pillars are natural
signals,
naturally
interpreted,
without any need to be conscious of them. I call the use of natural
signals natural
design.
(5)
Other problems concern the mappings
between
what you want to do and what appears possible.
(8) Visibility
indicates the mapping between intended actions and actual operations.
The Psychology of Everyday Things
AFFORDANCES
Definition of affordance as perceived or actual property determining range of uses.
(9) affordance refers to the perceived and actual properties of the thing, primarily those fundamental properties that determined just how the thing could possibly be used.
TWENTY
THOUSAND EVERYDAY THINGS
(12)
Here is where the designer's knowledge of the psychology of people
coupled with knowledge of how things work becomes crucial.
CONCEPTUAL MODELS
Principles of Design for Understandability and Usability
PROVIDE A GOOD CONCEPTUAL MODEL
Conceptual models include design model, users model, and resulting system images.
(16)(figure 1.10) Conceptual Models. The design model is the designer's conceptual model. The user's model is the mental model developed through interaction with the system. The system image results from the physical structure that has been built (including documentation, instructions, and labels). . . . If the system image does not make the design model clear and consistent, then the user still end up with the wrong mental model.
MAKE
THINGS VISIBLE
(22)
Whenever the number of possible actions exceeds the number of
controls, there is apt to be difficulty.
THE
PRINCIPLE OF MAPPING
(23)
Mapping
is
a technical term meaning the relationship between two things, in this
case between the controls and their movements and the results in the
world.
(23) Natural mapping, by which I mean taking advantage of
physical analogies and cultural standard, leads to immediate
understanding.
(25) A device is easy to use when there is
visibility to the set of possible actions, where the controls and
displays exploit natural mappings.
THE
PRINCIPLE OF FEEDBACK
(27)
Feedback - sending back to the user information about what action has
actually been done, what result has been accomplished - is a
well-known concept in the science of control and information theory.
Paradox of technology that added complexity accompanies added functionality.
(27) To be fair, these new designs are pushing hard on the paradox of technology: added functionality generally comes along at the price of added complexity.
Pity the Poor Designer
The
Paradox of Technology
(30)
The development of a technology tends to follow a U-shaped curve of
complexity: starting high; dropping to a low, comfortable level; then
climbing again.
(31) Whenever the number of functions and required
operations exceeds the number of controls, the design becomes
arbitrary, unnatural, and complicated. 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.
CHAPTER TWO
THE PSYCHOLOGY OF EVERYDAY ACTIONS
Falsely Blaming Yourself
(36)
If an error is possible, someone will make it. The designer must
assume that all possible errors will occur and design so as to
minimize the chance of the error in the first place, or its effects
once it gets made. Errors should be easy to detect, they should have
minimal consequences, and, if possible, their effects should be
reversible.
Misconceptions of Everyday Life
ARISTOTLE'S NAIVE PHYSICS
PEOPLE
AS EXPLANATORY CREATURES
(39)
everyone forms theories (mental models) to explain what they have
observed. In the case of the thermostat, the design gives absolutely
no hint as to the correct answer. In the absence of external
information, people are free to let their imaginations run free as
long as the mental models they develop account for the facts as they
perceive them.
Blaming
the Wrong Cause
(40)
The psychology of blame (or, to be more accurate, of attribution) is
complex and not fully understood. In part, there seems to have to be
some perceived causal relationship between the thing being blamed and
the result. The word perceived
is
critical: the causal relationship does not have to exist; the person
simply has to think it is there.
(41) Interestingly enough, the
common tendency to blame ourselves for failures with everyday objects
goes against normal attributions people make. In general, it has been
found that people attribute their own problems to the environment,
those of other people to their personalities.
LEARNED HELPLESSNESS
TAUGHT HELPLESSNESS
One of the foils of ambition, taught helplessness processes evident in mathematics curriculum and also with technologies.
(43) Or consider the normal mathematics curriculum, which continues relentlessly on its way, each new lesson assuming full knowledge and understanding of all that has passed before. Even though each point may be simple, once you fall behind it is hard to catch up. The result: mathematics phobia. Not because the material is difficult, but because it is taught so that difficulty in one stage hinders further progress. The problem is that once failure starts, it soon generalizes by self-blame to all of mathematics. Similar processes are at work with technology. The vicious cycle starts: if you fail at something, you think it is your fault. Therefore you think you can't do the that task. As a result, next time you have to do the task, you believe you can't so you don't even try.
The Nature of Human Thought and Explanation
How People Do Things: The Seven Stages of Action
Seven stages of action for how people do things provides basic checklist for design aids, routing around gulfs of execution and evaluation.
(48) Forming the goal; Forming the intention; Specifying an action; Executing the action; Perceiving the state of the world; Interpreting the state of the world; Evaluating the outcome.
The Gulfs of Execution and Evaluation
THE GULF OF EXECUTION
(51)
The difference between the intentions and the allowable actions is
the Gulf of Execution.
THE GULF OF EVALUATION
(51)
The Gulf of Evaluation reflects the amount of effort that the person
must exert to interpret the physical state of the system and to
determine how well the expectations and intentions have been met.
The Seven Stages of Action as Design Aids
(52)
The seven-stage structure can be a valuable design aid, for it
provides a basic checklist of questions to ask to ensure that the
Gulfs of Evaluation and Execution are bridged.
CHAPTER
THREE
KNOWLEDGE IN THE HEAD AND IN THE WORLD
(54-55)
not all of the knowledge required for precise behavior has to be in
the head. It can be distributed - partly in the head, partly in the
world, and partly in the constraints of the world. Precise behavior
can emerge from imprecise knowledge for four reasons: 1. Information
in the world 2.
Great precision is not required
3.
Natural constraints are present
4.
Cultural constraints are
present.
(56)
There is a tradeoff between the amount of mental knowledge and the
amount of external knowledge required in performing tasks.
Precise Behavior from Imprecise Knowledge
INFORMATION
IS IN THE WORLD
(56)
There is a tradeoff between speed and quality of performance and
mental effort.
Compare knowledge in head and in the world to explicit versus implicit knowledge.
(57-58) 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. . . . Declarative knowledge is easy to write down and to teach. Knowledge how – what psychologists call procedural knowledge – is the knowledge that enables a person to perform music, to stop a car smoothly with a flat tire on an icy road . . . Procedural knowledge is difficult of impossible to write down and difficult to teach. It is best taught by demonstration and best learned through practice.
GREAT PRECISION IS NOT REQUIRED
THE POWER OF CONSTRAINTS
Point also made by Ong about power of constraints; more important is inconsideration (unthought) of audio virtual realities created by unnatural code.
(60) Combining the two constraints of rhyme and meaning can therefore reduce the information about the particular word that must be kept in memory to nothing; as long as the constraints are known, the choice of word can be completely determined.
Also consider stickiness of memory when what is being learned relates or does not relate to the overall context of activities of which the learning is a part; see page 67 on the difficulty with organizing long term memory.
(61) The notion that someone should be able to recite word for word is relatively modern. Such a notion can be held only after printed texts become available; otherwise who could judge the accuracy of a recitation?
Testing an ordering of hyperlinks through the public content leads to editing the notes for Johnson after seeing multiple links between earlier, banal analysis of stickiness of memory to recent banal work on long term memory creation and maintenance that should be applied to UCF ignoring Moodle.
Both Johnson and Ong nod toward alien phenomenology expressing state of the art methodology in digital humanities scholarship including for critical theory and invention in texts and technology.
(61) Most of us do not learn epic poems. But we do make use of strong constraints that serve to simplify what must be retained in memory. Consider an example from a completely different domain: taking apart and reassembling a mechanical device.
Memory is Knowledge in the Head
THE CONSPIRACY AGAINST MEMORY
THE
STRUCTURE OF MEMORY
(67)
The difficulty with LTM is in organization – in getting material in
and in figuring out how to retrieve it – not in capacity. Storage
and retrieval are easier when the material makes sense, when it fits
into what is already known.
(67) If we examine how people use
their memories and how they retrieve information, we discover a
number of categories: Memory
for arbitrary things, Memory for meaningful relationship, Memory
through explanation.
MEMORY FOR ARBITRARY THINGS
Relate this and challenges of LTM to stickiness of memory discussion in research paper from Project Management for Technical Writers.
(67) Arbitrary knowledge can be classified as the simple remembering
of what is to be done, without reliance on an understanding of why or
on internal structure.
(68) People who have learned to use
computers or cook by rote are probably not very good. Since they do
not understand the reasons for their actions, they must find tasks
arbitrary and strange. When something goes wrong, they don't know
what to do (unless they've memorized solutions).
MEMORY FOR MEANINGFUL RELATIONSHIPS
MEMORY THROUGH EXPLANATION
(70)
People probably make up mental models for most of the things they do.
This is why designers should provide users with appropriate models:
when they are not supplied, people are likely to make up
inappropriate ones.
Memory Is Also Knowledge in the World
REMINDING
Is this the distinction Plato intends in Phaedrus, that reminding involves knowledge in the world, or the two aspects signal and message?
(72) One of the most important and interesting aspects of the role of
external memory is reminding, a good example of the interplay between
knowledge in the head and in the world.
(73) A good reminding
method is to put the burden on the thing itself.
(73) There are
two different aspect to reminder: the signal and the message.
(74)
I am waiting for the day when portable computers become small enough
that I can keep one with me at all times.
NATURAL MAPPINGS
(75) The
arrangement of burners and controls on the kitchen stove provides a
good example of the power of natural mappings to reduce the need for
information in memory.
(78) Wherever labels seem necessary,
consider another design.
(78) Usability is not often thought of as
a criterion during the purchasing process.
The Tradeoff between Knowledge in the World and in the Head
(80)
Reminders provide a good example of the relative tradeoffs between
the roles of internal versus external knowledge. Knowledge in the
world is accessible. . . . Knowledge in the mind is ephemeral.
CHAPTER FOUR
KNOWING WHAT TO DO
A Classification of Everyday Constraints
(84)
for different classes of constraints - physical, semantic, cultural,
and logical. These classes are apparently universal, appearing in a
wide variety of situations, and sufficient.
PHYSICAL CONSTRAINTS
(84)
Physical limitations constrain possible operations. . . . The value
of physical constraints is that they rely upon properties of the
physical world for their operation; no special training is necessary.
SEMANTIC CONSTRAINTS
(85)
Semantic constraints rely upon the meaning of the situation to
control the set of possible actions. . . . Semantic constraints rely
upon our knowledge of the situation and of the world.
CULTURAL CONSTRAINTS
(85)
Cultural issues are at the root of many of the problems we have with
new machines: there are as yet no accepted conventions or customs for
dealing with them.
(85-86) guidelines for cultural behavior are
represented in the mind by means of schemas, knowledge structures
that contain the general rules and information necessary for
interpreting situations and for guiding behavior.
LOGIAL CONSTRAINTS
(86)
Natural mappings work by providing logical constraints. There are no
physical or cultural principles here; rather there is a logical
relationship between the spatial or functional layout of components
and the tings that they affect or are affected by.
Applying Affordances and Constraints to Everyday Objects
THE PROBLEM WITH DOORS
THE PROBLEM WITH SWITCHES
WHICH SWITCH CONTROLS WHICH FUNCTION?
HOW ARE THE SWITCHES ARRANGED?
Visibility and Feedback
MAKING VISIBLE THE INVISIBLE
(101)
Nothing succeeds like visual feedback, which in turn requires a good
visual display.
USING SOUND FOR VISIBILITY
(103)
Natural sounds reflect the complex interaction of natural
objects.
(103) If they are to be useful, sounds must be generated
intelligently, with an understanding of the natural relationship
between the sounds and the information to be conveyed.
(103) One
of the virtues of sounds is that they can be detected even when
attention is applied elsewhere. But this virtue is also a deficit,
for sounds are often intrusive.
CHAPTER FIVE
TO ERR IS HUMAN
Recall von Neumann discussions about error tolerance of natural and artificial automata.
(105) People make errors routinely. Hardly a minute of normal
conversation can be by without a stumble, a repetition, a phrase
stopped midway through to be discarded or redone. Human language
provides special mechanisms that make corrections so automatic that
the participants hardly take notice; indeed, they may be surprised
when errors are pointed out. Artificial devices do not have the same
tolerance. Push the wrong button, and chaos may result.
(105)
Slips result from automatic behavior, when subconscious actions that
are intended to satisfy our goals get waylaid en route. Mistakes
result from conscious deliberations.
(105) Form an appropriate
goal but mess up in the performance, and you've made a slip. . . .
Form the wrong goal, and you've made a mistake.
Slips
Footnote on Sherry Turkle The Second Self confirms that Freud slips are reinterpreted.
(106) Some slips may indeed have hidden, darker meanings, but most
are accounted for by rather simple events in our mental
mechanisms.
(106) Slips show up most frequently in skilled
behavior. . . . On the whole, people can consciously attend to only
one primary thing at a time. . . . We can do more than one thing at a
time only if most of the actions are done automatically,
subconsciously, with little or no need for conscious attention.
TYPES OF SLIPS
This is an excellent enumeration of six types of slips but not doing justice to Freuds insight into their nature; Freud would certainly pay attention to all types of slips, not just associative action errors.
(107)
We
can place slips into one of six categories: capture errors,
description of errors, data-driven errors, associative activation
errors, loss-of-activation errors, and mode errors.
(107)
The capture error appears whenever two different action sequences
have their initial stages in common, with one sequence being
unfamiliar and the other being well practiced. Seldom, if ever, does
the unfamiliar sequence capture the familiar one.
(108)
Description errors usually result in performing the correct action on
the wrong object.
(108) Description errors occur most frequently
when the wrong and right objects are physically near each
other.
(109) Automatic actions are data driven - triggered by the
arrival of the sensory data. But sometimes data-drive activities can
intrude into an ongoing action sequence, causing behavior that was
not intended.
(109) Associate activation errors are the slips
studied by Freud; you think something that ought not to be said and
then, to your embarrassment, you say it.
(110) Lack-of-activation
errors occur because the presumed mechanism - the “activation” of
the goals - has decayed. The less technical but more common term
would be “forgetting.”
How about some examples of human equivalents of mode errors: different uses of body parts, for example, for sex?
(110) Mode errors occur when devices have different modes of operation, and the action appropriate for one mode has different meanings in other modes. Mode errors are inevitable any time equipment is designed to have more possible actions than it has controls or displays, so the controls must do double duty.
DETECTING SLIPS
(110-111)
detection can only take place if there is feedback. . . . Some trail
of the sequence of actions that was performed is valuable.
(111)
The most global description (the one at the top of the list), is
called the high-level specification. The more detailed descriptions,
the ones at the bottom of the list, are called the low-level
specifications. Any one of them might be in error.
(112) In all
the situations I have examined the error correction mechanism seems
to start at the lowest possible level and slowly works its way
higher.
DESIGN LESSONS FROM THE STUDY OF SLIPS
(113)
In computer systems, it is common to prevent errors by requiring
confirmation before a command will be executed, especially when the
action will destroy a file. But the request is ill timed; it comes
just after the person has initiated the action and is still fully
content with the choice. . . . The user has requested deletion of the
wrong file but the computer's request for confirmation is unlikely to
catch the error; the user is confirming the action, not the file
name. Thus asking for confirmation cannot catch all slips. It would
be more appropriate to eliminate irreversible actions.
(114) When
you build an error-tolerant mechanism, people come to rely upon it,
so it had better be reliable.
Mistakes as Errors of Thought
SOME
MODELS OF HUMAN THOUGHT
(114-115)
Even though principles of rationality seem as often violated as
followed, we still cling to the notion that human thought should be
rational, logical, and orderly. . . . Many scientists who study
artificial intelligence use the mathematics of formal logic - the
predicate calculus - as their major tool to simulate thought.
(115)
But human thought - and its close relatives, problem solving and
planning - seem more rooted in past experience than in logical
deduction. Mental life is not neat and orderly. It does not proceed
smoothly and gracefully in neat, logical form. Instead, it hops,
skips, and jumps its way from idea to idea. . . . it is the
difference that leads to creative discovery and to great robustness
of behavior.
(115) Human memory is most definitely not like a set
of photographs or a tape recording. It mushes things together too
much, confuses one event with another, combines different events, and
leaves out parts of individual events.
File cabinet model of human thought.
(115-116) Another theory is based on the filing cabinet model, wherein there are lots of cross references and pointers to other records. . . . Of course, it is not called a file cabinet theory. It goes by the names of “schema theory,” “frame theory,” or sometimes “semantic networks” and “propositional encoding.” The individual file folders are defined in the formal structure of the schemas or frames, and the connections and associations among the individual records make the structure into a vast and complex network. The essence of the theory consists of three beliefs, all reasonable and supported by considerable evidence: (1) that there is logic and order to the individual structures (this is what the schema or frame is about); (2) that human memory is associative, with each schema pointing and referring to multiple others to which it is related or that help define the components (thus the term “network”); and (3) that much of our power for deductive thought comes from using the information in one schema to deduce the properties of another (thus the term “propositional encoding”).
THE
CONNECTIONIST APPROACH
(116)
A newer approach is rooted in the working of the brain itself. Those
of us who follow this new approach call it “connectionism,” but
it also goes under the names of “neural nets,” “neural models,”
and “parallel distributed processing.” .. This approach follows
the rules of thermodynamics more than it does the rules of logic.
Interactions as computational part of thought under connectionist approach.
(117)
We
can think of the interactions as the computational part of thought:
when one set of units sends signals activating another, this can be
interpreted as offering support for a cooperative interpretation of
events; when one set of units sends signals suppressing another, it
is because the two usually offer competing interpretations. The
result of all this support and competition is a compromise: not the
correct interpretation, simply one that is as consistent as possible
with all possibilities under active consideration. This approach
suggests that much of thought results from a kind of pattern matching
system, one that forces its solutions to be analogous to past
experiences, and one that does not necessarily follow the formal
rules of logical inference.
(118) Throw everything into memory on
top of one another. That is a crude approximation of the
connectionist approach to memory.
(118) We must together details
of things that are similar, and give undue weight to the discrepant.
We relish discrepant and unusual memories.
(119) This event-based
reasoning is powerful, yet fundamentally flawed. Because thought is
based on what can be recalled, the rare event can predominate.
The Structure of Tasks
WIDE AND DEEP STRUCTURES
(121)
Everyday structures are either shallow or narrow.
SHALLOW STRUCTURES
(121)
There are many alternative actions, but each is simple; there are few
decisions to make after a single top-level choice.
NARROW STRUCTURES
(121)
If each possibility leads to only one or tow further choices, then
the resulting tree structure can be said to be narrow and deep.
(123)
Any task that involves a sequence of activities where the action to
be done at any point is determined by its place in the sequence is an
example of a narrow structure.
THE NATURE OF EVERYDAY TASKS
Conscious and Subconscious Behavior
(125)
Subconscious thought is biased toward regularity and structure, and
it is limited in formal power. It may not be capable of symbolic
manipulation, of careful reasoning through a sequence of steps.
(126)
Conscious thought tends to be slow and serial. Conscious processing
seems to involve short-term memory and is thereby limited in the
amount that can be readily available.
(127) Which is exactly what
everyday tasks ought to be - boring, so that we can put our conscious
attention on the important things of life, not the routine.
EXPLAINING AWAY ERRORS
(128)
When there is a devastating accident, people's explaining away the
signs of the impending disaster always seems implausible to others.
SOCIAL PRESSURES AND MISTAKES
(129)
In industrial settings social pressures can lead to
misinterpretations, mistakes, and accidents. For understanding
mistakes, social structure is every bit as essential as physical
structure.
Designing for Error
(131)
Designers make the mistake of not taking error into account.
Inadvertently, they can make it easy to err and difficult or
impossible to discover error or to recover from it. . . . Don't think
of the user as making errors; think of the actions as approximations
of what is desired.
(131) Design so that errors are easy to
discover and corrections are possible
HOW
TO DEAL WITH ERROR - AND HOW NOT TO
(132)
Warnings and safety methods must be used with care and intelligence,
taking into account the tradeoffs for the people who are affected.
FORCING FUNCTIONS
Forcing functions: interlocks, lockins, lockouts constrain action so failure at one stage prevents next step.
(132)
Forcing functions are a form of physical constraint: situations in
which the actions are constrained so that failure at one stage
prevents the next step from happening.
(125) Forcing functions are
the extreme case of strong constraints that make it easy to discover
erroneous behavior. . . . In the field of safety engineering, forcing
functions show up under other names, in particular as specialized
methods for the prevention of accidents. Three such methods are
interlocks,
lockins, and
lockouts.
(137)
Forcing functions almost always are a nuisance in normal usage. The
clever designer has to minimize the nuisance value while retaining
the safety, forcing-function mechanism, to guard against the
occasional tragedy.
A Design Philosophy
Design philosophy should treat interaction as cooperative endeavor between person and machine taking into account possible misconceptions arising on either side: symbiotic components versus alien opponents.
(140) The designer shouldn't think of a simple dichotomy between errors and correct behavior; rather, the entire interaction should be treated as a cooperative endeavor between the person and machine, one in which misconceptions can arise on either side. This philosophy is much easier to implement on something like a computer which has the ability to make decisions on its own than on things like doors and power plants, which do not have such intelligence. . . . Put the required knowledge in the world. . . . Use the power of natural and artificial constraints: physical, logical, semantic, and cultural. Use forcing functions and natural mappings. Narrow the gulfs of execution and evaluation.
CHAPTER SIX
THE DESIGN CHALLENGE
The Natural Evolution of Design
FORCES THAT WORK AGAINST EVOLUTIONARY DESIGN
(142)
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.
THE TYPEWRITER: A CASE HISTORY IN THE EVOLUTION OF DESIGN
(147)
In the end, the qwerty keyboard was adopted throughout the world with
but minor variations. We are committed to it, even though it was
designed to satisfy constraints that no longer apply, was based on a
style of typing no longer used, and is difficult to learn.
(150)
Once a satisfactory product has been achieved, further change may be
counterproductive, especially if the product is successful.
Why Designers Go Astray
(151)
First, the reward structure of the design community tends to put
aesthetics first. . . . Second, designers are not typical users. . .
. Third, designers must please their clients, and the clients may not
be the users.
PUTTING AESTHETICS FIRST
(151-152)
Because prizes tend to be given for some aspects of a design, to the
neglect of all others - usually including usability.
DESIGNERS
ARE NOT TYPICAL USERS
(156)
In their work, designers often become expert with the device
they
are designing. Users are often expert at the task
they
are trying to perform with the device.
THE DESIGNER'S CLIENTS MAY NOT BE USERS
(157)
The state of California requires by law that universities purchase
things on a price basis; there are no legal requirements regarding
understandability or usability of the product.
The Complexity of the Design Process
DESIGNING FOR SPECIAL PEOPLE
The handwriting example is great: the social convention of left to write scansion smudges.
(162) Some problems are not solved by adjustments. Left-handed
people, for example, present special problems.
(164) designing for
flexibility helps.
SELECTIVE ATTENTION: THE PROBLEM OF FOCUS
(165)
When there is a problem, people are apt to focus on it to the
exclusion of other factors. The designer must design for the problem
case, making other factors more salient, or easier to get to, or
perhaps less necessary.
(165) A corollary principle is that
designers must guard against the problems of focus in their own
design.
The Faucet: A Case History of Design Difficulties
(170)
If you can't put the knowledge on the device, then develop a cultural
constraint: standardize what has to be kept in the head.
Two Deadly Temptations for the Designer
CREEPING FEATURISM
(173)
Creeping featurism is the tendency to add to the number of features
that a device can do, often extending the number beyond all
reason.
(174) The proper division of a complex set of controls
into modules allows you to conquer complexity.
THE WORSHIPPING OF FALSE IMAGES
(177)
the false image is appearance of technical sophistication.
The Foibles of Computer Systems
Typical criticism of FOSS is lack of expertise designing for nonprofessionals to use.
(177) There is nothing particularly special about the computer; it is a machine, a human artifact, just like the other sorts of things we have looked at, and it poses few problems that we haven't encountered already. But designers of computer systems seem particularly oblivious to the needs of users, particularly susceptible to all the pitfalls of design. The professional design community is seldom called in to help with computer products. Instead, design is left in the hands of engineers and programmers, people who usually have no experience, and no expertise in designing for people.
HOW TO DO THINGS WRONG
(179)
DO you want to do things wrong? Here is what to do: Make things
invisible; Be arbitrary; Be inconsistent; Make operations
unintelligible; Be impolite; Make operations dangerous.
IT'S NOT TOO LATE TO DO THINGS RIGHT
(180)
the best computer programs are the ones in which the computer itself
“disappears,” in which you work directly on the problem without
having to be aware of the computer.
COMPUTER AS CHAMELEON
EXPLORABLE SYSTEMS: INVITING EXPERIMENTATION
(183)
One important method of making systems easier to learn and to use is
to make them explorable, to encourage the user to experiment and
learn the possibilities through active exploration.
TWO MODES OF COMPUTER USAGE
Heim would argue strongly against this equivocating the computer as an ordinary tool; recommendation by Norman of designing software such that the computer disappears and the task is foregrounded allows concealing of enframing, recall Hegel worn sock is better than a mended one; not so with metaphysics.
(184) The point cannot be overstressed: make the computer system invisible. This principle can be applied with any form of system interaction, direct or indirect.
THE INVISIBLE COMPUTER OF THE FUTURE
CHAPTER SEVEN
USER-CENTERED DESIGN
Seven Principles for Transforming Difficult Tasks into Simple Ones
USE BOTH KNOWLEDGE IN THE WORLD AND KNOWLEDGE IN THE HEAD
THREE CONCEPTUAL MODELS
THE ROLE OF MANUALS
SIMPLIFY THE STRUCTURE OF TASKS
KEEP THE TASK MUCH THE AME, BUT PROVIDE MENTAL AIDS
USE TECHNOLOGY TO MAKE VISIBLE WHAT WOULD OTHERWISE BE INVISIBLE,
THUS IMPROVING FEEDBACK AND THE ABILITY TO KEEP CONTROL
(192)
With modern computers and their powerful graphic displays, we now
have the power to show what is really happening, to provide a good,
complete image that matches the person's mental model of the task -
thereby simplifying both understanding and performance.
(193) if
the skill is easily automated, it wasn't essential.
(193) In
general, I welcome any technological advance that reduces my need for
mental work but still gives me the control and enjoyment of the task.
. . . I want to use my mental powers for the important things, not
fritter them away on the mechanics.
AUTOMATE, BUT KEEP THE TASK MUCH THE SAME
CHANGE THE NATURE OF THE TASK
(194)
In general, technology can help transform deep, wide structures into
narrower, shallower ones.
(194) The introduction of new fastening
materials - for example, Velcro hook-and-loop fasteners - has
eliminated the need for a complex sequence of skilled motor actions
by changing the task to one this is considerably simpler, one that
requires less skill.
Heim examines this shift in psychic framework in much more detail.
(195-196) Digital timepieces are controversial: in changing the
representation of time, the power of the analog form has been lost,
and it has become more difficult to make quick judgments about
time.
(196) Today, because we can no longer remember the origins,
we think of the analog system as necessary, virtuous, and proper. It
presents a horrid, classic example of the mapping problem.
DON'T TAKE AWAY CONTROL
Supervisory control models, and closed-loop feedback.
(197) One problem is that overreliance on automated equipment can
eliminate a person's ability to function without it. . . . A second
problem is that a system may not always do things exactly the way we
would like, but we are forced to accept what happens because it is
too difficult (or impossible) to change the operation. A third
problem is that the person becomes a servant of the system, no longer
able to control or influence what is happening.
(197) All tasks
have several layers of control. . . . Sometimes we really want to
maintain control at the lower level. . . . At other times we want to
concentrate on higher level things.
MAKE THINGS VISIBLE: BRIDGE THE GULFS OF EXECUTION AND EVALUATION
GET THE MAPPINGS RIGHT
(199)
Natural mappings are the basis of what has been called “response
compatibility” within the fields of human factors and ergonomics. .
. . Difficulties arise wherever the positioning and movements of the
controls deviate from strict proximity, mimicry, or analogy to the
things being controlled.
EXPLOIT THE POWER OF CONSTRAINTS, BOTH NATURAL AND ARTIFICIAL
DESIGN FOR ERROR
WHEN ALL ELSE FAILS, STANDARDIZE
(201)
standardization is essential only when all the necessary information
cannot be placed in the world or when natural mappings cannot be
exploited.
STANDARDIZATION AND TECHNOLOGY
(202)
Standardization is simply another aspect of cultural
constraints.
(202) Today's computers are still poorly designed, at
least from the user's point of view. But on problem is simply that
the technology is still very primitive - like the 1906 auto - and
there is no standardization.
THE TIMING OF STANDARDIZATION
(202)
Standardize and you simplify lives: everyone learns the system only
once. But don't standardize too soon: you may be locked into a
primitive technology, or you may have introduced rules that turn out
to be grossly inefficient, even error-inducing. Standardize too late
and there may already be so many ways of doing the task that no
international standard can be agreed on; if there is agreement on an
old-fashioned technology, it may be too expensive to change. The
metric system is a good example.
Deliberately Making Things Difficult
DESIGNING A DUNGEONS AND DRAGONS GAME
(208)
making things difficult is a tricky business. . . . several
psychological factors hang in a delicate balance: challenge,
enjoyment, frustration, and curiosity.
EASY LOOKING IS NOT NECESSARILY EASY TO USE
(209)
Complexity of appearance seems to be determined by the number of
controls, whereas difficulty of use is jointly determined by the
difficulty of finding the relevant controls (which increases with the
number of controls) and difficulty of executing the functions (which
may decrease with the number of controls).
(209) Hide the controls
not being used at the moment.
Design and Society
HOW WRITING METHOD AFFECTS STYLE
FROM QUILL AND INK TO KEYBOARD AND MICROPHONE
(211)
Style may change further when we get voice typewriters, where our
spoken words will appear on the page as they are spoken.
(211) On
the one hand, it is satisfying to be able to type your thoughts
without worrying about minor typographical errors or spelling. On the
other hand, you may spend less time thinking and planning.
OUTLINE PROCESSORS AND HYPERTEXT
Reaches similar conclusions as Heim for outline processors and hypertext, but not at the same depth of ontological analysis.
(211) The current fad in writing aids is the outline processor, a
tool designed to encourage planning and reflection on the
organization of material. . . . Outline processors attempt to
overcome organizational problems by allowing collapsed views of the
manuscript to be examined and manipulated. But the process seems to
emphasize the organization that is visible in the outline or heading
structure of the manuscript, thereby deemphasizing other aspect of
the work. It is characteristic of thought processes that attention to
one aspect comes at the cost of decreased attention to others.
(212)
Hypertext makes a virtue of lack of organization, allowing ideas and
thoughts to be juxtaposed at will.
(212) Imagine that this book
was in hypertext. How would it work? Well, I've used several devices
that relate to hypertext: one is the footnote, another is
parenthetical comments, and yet another is contrasting text.
(213)
If hypertext really becomes available, especially in the fancy
versions now being talked about - where words, sounds, video,
computer graphics, simulations, and more are all available at the
touch of the screen - well, it is hard to imagine anyone capable of
preparing the material. It will take teams of people.
THE HOME OF THE FUTURE: A PLACE OF COMFORT OR A NEW SOURCE OF
FRUSTRATION
(214) it is
difficult to see how the complex instructions required for such a
system will be conveyed.
The Design of Everyday Things
(216)
Design, therefore, takes on political significance. . . . In Western
cultures, design has reflected the capitalistic importance of the
marketplace, with an emphasis on exterior features deemed to be
attractive to the purchaser. . . . We are surrounded with objects of
desire, not objects of use.
Feenberg tie-in to go along with the Heim tie-in: cry for usable products connects to democratic rationalization?
(216) If you are a designer, help fight the battle for usability. If you are a user, then join your voice with those who cry for usable products.
Norman, Donald A. (2002). The Design of Everyday Things. United States: Basic Books.
Norman, Donald A. The Design of Everyday Things. United States: Basic Books. 2002. Print.