September 6, 2014

[notes] The Design of Everyday Things

The Design of Everyday Things (2002) by Donald A. Norman #

NOTE: Bewarned, these notes are un-edited, un-revised, and un-styled. I plan on cleaning them up eventually, but until then, I apologize.

The Psychopathology of Everyday Things #

Discoverability: What actions are possible?

Understanding: How is the product supposed to be used?

Industrial design - professional service of creating and developing concepts and specifications that optimize the functional, value and appearance of products and systems for the mutual benefit of both the user and manufacturer

Interaction design - focuses on how people interact with technology

Experience design - practice of designing products, processes, services, events, and environments with a focus placed on the quality and enjoyment of the total experience

Interaction between people and machines is interesting:

people are creative, but not precise
machines are precise, but not creative

Human-Centered Design (HCD)

process for approaching design
focuses on a usability perspective
relies on communication

Affordances: a relationship between an object and an agent that determines how the object can be used

i.e. a chair affords sitting for humans
note that affordances are not properties, they are functions of an agent
i.e. a chair does not afford sitting for elephants

Anti-affordance: preventing an agent from being able to use an object in a certain way

i.e. glass anti-affords passage for humans (it blocks them)

Signifiers: a communication of the existence and proper usage of an affordance

can be deliberate, or unintentional

Affordances: the possible interactions between people and the environments

some are perceivable and others are not

Perceived affordances: act as signifiers, but can be ambiguous

Signifiers: signal what actions are possible and how they should be done

must be perceivable

Mapping: relationship between the elements of two sets of things

natural mappings are intuitive, perhaps because they take advantage of spatial analogies

Feedback: communicating the results of an action

should be immediate (within .1 seconds)
both too much and too little feedback can be detrimental

Conceptual Models: an explanation of how something works

often highly simplified
often not completely accurate
conceptual model is often constructed based on signifiers, affordances, constraints, and mappings

“Good conceptual models are the key to understandable, enjoyable products: good communication is the key to good conceptual models.”

The Psychology of Everyday Actions #

When people try to do things they face the:

Gulf of Execution - figuring out what to do to achieve what you want
Gulf of Evaluation - figuring out what happened

The Seven Stages of Action #

form the goal
plan the action
specify the action sequence
perform the action sequence (state of the world changes)
perceive the state of the world
interpret the perception
compare the outcome with the goal

these actions bridge the gap between our goals and what we do to achieve those goals
the process can be top down or bottom up
top down => goal-driven behavior - desiring a change in the world
bottom up => data-driven or event-driven behavior - responding to a change in the world
many everyday tasks are opportunistic - where behavior takes advantage of circumstance

Root cause analysis - a process for determining the root goal
“People don’t want to buy a quarter-inch drill. They want a quarter inch hole!” ~ Theodore Levitt

Human Thought: Mostly Subconscious #

Subconscious

fast, automatic, uses multiple resources, and controls skilled behavior

Conscious

slow, controlled, uses limited resources
invoked in novel situations, when learning, when in danger, when things go wrong
both conscious and subconscious are necessary
both can err

“Emotion and cognition are tightly intertwined”

“Emotion interacts with cognition biochemically”

positive (relaxed) emotional state is good for creative thought
negative (tense) emotional state is good for getting things done

Three levels of processing

Visceral
makes quick judgements about the environment
fast and completely subconscious
sensitive only to the current state of things
highly coupled to body’s musculature (we often determine our own body state by reading our musculature)
causes animals to fight or flee
for designers, this is about immediate perception
every action is associated with an expectation (designers should use feedback to achieve this)
Behavioral
learned skills, triggered by situations that match the appropriate patterns
we are often aware of the goal, but unaware of the details
Reflective
conscious cognition
deep understanding, reasoning, and conscious decision making
evaluates circumstance, actions and outcomes
where highest levels of emotion take place (causes are assigned and predictions of the future take place)
where blame and praise are assigned (where as a product might earn a recommendation to a friend)
memories are more important than reality

“The stages of action can readily be associated with the three different levels of processing. At the lowest level are the visceral levels of calmness or anxiety when approaching a task or evaluating the state of the world. Then, in the middle level, are the behavioral ones driven by expectations on the execution side - for example, hope and fear - and emotions driven by the confirmation of those expectations on the evaluations side - for example, relief or despair. At the highest level are the reflective emotions, ones that assess the results in terms of the presumed causal agents and the consequences, both immediate and long term. Here is where satisfaction and pride occur, or perhaps blame and anger.”

Flow: complete immersion in an activity

“the results of our actions are evaluated against expectations and the resulting emotion affects our feelings as we continue through many cycles of the action”
easy task -> easy to meet expectations -> boredom
hard task -> many failed expectations -> anger and giving up -> learned helplessness
flow is the perfect middle ground

Falsely blaming yourself #

eliminate the term human error
instead, talk about communication and interaction
think of the interaction between a person and a machine as a collaboration
design error => when humans fail to meet arbitrary, inhuman requirements of machines
when you fail at using a product, consider the chance that it’s the fault of design

Feedforward: the information that helps answer questions of execution

Feedback: aids in the understanding of what has happened

Seven fundamental principles of design

Discoverability: It is possible to determine what actions are possible and the current state of the device.
Feedback: There is full and continuous information about the results of actions and the current state of the product or service. After an action has been executed, it is easy to determine the new state.
Conceptual Model: The design projects all the information needed to create a good conceptual model of the system, leading to understanding and a feeling of control. The conceptual model enhances both discoverability and evaluation of results.
Affordances: The proper affordances exist to make the desired actions possible.
Signifiers: Effective use of signifiers ensures discoverability and that the feedback is well communicated and intelligible.
Mappings: The relationship between controls and their actions follows the principles of good mapping, enhanced as much as possible through spatial layout and temporal contiguity.
Constraints: Providing physical, logical, semantic, and cultural guides actions and eases interpretation.

Knowledge in the Head and in the World #

Precise Behavior from Imprecise Knowledge #

because:

Knowledge is both in the head and in the world
we can derive knowledge from the structure of the world
we embed knowledge by structuring the world around us
Great precision is not required
“Perfect behavior results if the combined knowledge in the head and in the world is sufficient to distinguish an appropriate choice from all others”
Natural constraints exist in the world
Knowledge of cultural constraints and conventions exists in the head
abstract artificial constraints imposed by society

Constraints Simplify Memory #

e.g. - the powerful constraints of poetry for memorizing epics

Paradox: Security

“The more complex the password requirements, the less secure the system.”
Because people don’t remember their own passwords, then write them down somewhere
safest to have two kinds of security (i.e. “something you have and something you own”)

The Structure or Working Memory #

Short-Term Working Memory

simplified model: think of it liking pointers in computer programming
humans have about 5 pointers
“To maximize efficiency of working memory it is best to present different information over different modalities: sight, sounds, touch (haptics), hearing, spatial location, and gestures.”

Long Term Memory

it takes time for information to get into LTM
sleep seems to play an important role
the size appears to be so large as to not impose any practical limit
“The way by which people retrieve needed knowledge probably involves some form of pattern-matching mechanism coupled with a confirmatory process that checks for consistency with the required knowledge.”
“retrieval is a reconstructive process, so it can be erroneous”
two categories
Memory for arbitrary things
Memory for meaningful things
meaningful things are easier to remember
because they mesh with pre-existing knowledge

“The most effective way of helping people remember is to make it unnecessary.”

“Knowledge in the world, external knowledge, is a valuable tool for remembering, but only if it is available at the right place, at the right time, in the appropriate situation.”

Reminding: Prospective Memory #

remembering to do some activity at a future time
two aspects to a reminder:
the signal - knowing that something is to be remembered (compare to knowing what can be done)
the message - remembering the information (compare to knowing how to do it)
time based reminders and location based reminders

Tradeoffs Between Knowledge in the World and in the Head #

Knowledge in the head

requires learning, which is made easier when there is meaning or structure to the material or if there is a good conceptual model
nothing need be visible, giving more flexibility to the designer

Knowledge in the world

interpretation substitutes for learning (but how easy the interpretation is depends on the designer)
can be ugly an inelegant, especially for large quantities, which leads to clutter

Memory in Multiple Heads, Multiple Devices #

knowledge and structure in the world can combine with knowledge and structure in the head to enhance memory performance
can potentially use multiple agents (people or machines) to aid this
seems to rely on quick iteration to constrain potential options

Natural Mappings #

best - controls mounted directly on item being controlled
also good - controls arranged in the same spatial configuration as the objects to be controlled
can differ with culture (i.e. different cultures have different conceptual models of time) (i.e. on computers do you drag the window, or do you drag the content)

Knowing What To Do: Constraints, Discoverability, and Feedback #

Constraints: constrain possible operations

physical: (i.e. this piece only fits in one spot)
cultural: allowable actions for social situations
semantic (meaning): rely upon the meaning of the situation
logical: (i.e. there is only one piece remaining)
cultural and semantic constraints can change with time

Activity-Centered Controls #

switches that control an activity
i.e. sets the room in “presentation mode” which effects the lights, audio volume, etc
can be tricky to get the activities right
must allow for flexible deviation

Constraints that Force the Desired Behavior #

Forcing Functions: actions are constrained so that failure at one stage prevents the next step from happening

form of physical constraint (?)
i.e. key and ignition in car

Interlocks: forces operations to take place in proper sequence

i.e. microwave turns off when you open the door

Lock-Ins: keeps an operation active, preventing someone from prematurely stopping it (stopping it until desired operations have been done)

Lockouts: prevents someone from entering a space that is dangerous, or prevents an event from occurring

often used for safety reasons

Conventions, Constraints, and Affordances #

“The interpretation of a perceived affordance is a cultural convention.”
“Conventions are a special kind of cultural constraint”

people invariably object and complain whenever a new approach is introduced into an existing array of products and systems

Human Error? No, Bad Design #

the most common cause of error is the nature of tasks and procedures that require people to behave in unnatural ways
interruptions are a common reason for error

Root Cause Analysis #

investigate the accident until the single, underlying cause is found
this process is often flawed, because it stops when it reaches human error
this mentality is often shared even by the person who committed the error
it should be taken further to find design error
can use the “five whys” approach

Deliberate Violation #

sometimes people take risks on purpose
“A major cause of violations is inappropriate rules or procedures that not only invite violation but encourage it.”
this can also result from social or cultural pressures

Types of Errors #

Human error: deviance from “appropriate” behavior

Slips: occurs when a person intends to do one action and ends up doing something else.
action-based => wrong action was performed
- capture slip => a situation where a more frequent or recently performed action gets performed instead of the desired action
- “Designers should avoid procedures that have identical opening steps but then diverge.”
- description-similarity slip => an error caused when the action is performed on the wrong item, usually one similar to the intended target
- “This happens when the description of the target is sufficiently vague.”
- mode-error slips => occurs when a device has different states in which the same controls have different meanings (we call these states modes)
- especially likely when the equipment doesn’t make the mode visible
memory lapse => intended action not done or results not evaluated
tend to occur more frequently to skilled people than to novices because the skilled people tend to perform automatically under subconscious control
Mistakes: occurs when the wrong goal is established or the wrong plan is formed
person makes a poor decision, misclassifies a situation, or files to take all the relevant factors into account
all following actions are part of the error because they follow an inappropriate intent
rule-based => person has appropriately diagnosed the situation, but then decided upon an erroneous course of action (the wrong rule is being followed)
knowledge-based => problem is misdiagnosed because or erroneous or incomplete knowledge
memory-lapse => takes place when there is forgetting at the stages of goals, plans, or evaluation

Modes of behavior

skill-based => occurs when workers are extremely expert at their jobs, so they can do the everyday routine tasks with little or no thought or conscious attention => most common error is slips
rule-based => occurs when the normal routine is no longer applicable but the new situation is one that is known, so there is already a well-prescribed course of action (a rule) => wrong rule selected is a mistake, improper execution of a rule is a slip
- the mistake usually comes from misclassification, which comes from natural human biases (e.g. recent events better remembered than older events)
knowledge-based => occur when unfamiliar events occur, where neither existing skills nor rules apply
- use a strong conceptual model, and focus on the interaction between human and machine

Errors can be understood in reference to the seven stages of the action cycle

mistakes happen at the high levels of cognition
slips happen at the lower levels
memory lapses happen at any of the transitions

Checklists #

useful tool to prevent errors
it’s usually bad to have a checklist that multiple people are responsible for going over (everybody assumes that the other people will catch their mistakes)

Reporting Error #

want to report error as quickly as possible
poka-yoke => error proofing

In Hindsight, Events Seem Logical #

they may not seem as logical in the moment

Designing for Error #

design to minimize the causes of error
do sensibility checks
make it possible to undo actions
make it easy to discover and correct errors
don’t treat the action as an error, instead think of the action as an approximation of what is desired

“People are flexible, versatile, and creative. Machines are rigid, precise, and relatively fixed in their operations. There is a mismatch between the two that can lead to enhanced capability if used properly.”

Design Principles

“Put the knowledge required to operate the technology in the world. ” But still try to make it efficient for people that have the knowledge in their head.
Use the power of natural and artificial constraints: physical, logical, semantic, and cultural. Exploit the power of forcing functions and natural mappings.
Bridge the Gulf of Execution and the Gulf of Evaluation. Make things visible, both for execution and evaluation. Provide feedforward and feedback. Make is possible to determine the system’s status readily, easily, accurately, and in a form consistent with the person’s goals, plans, and expectations.

The Swiss Cheese Model of How Errors Lead to Accidents #

basically many errors need to align without being corrected to result in an accident
to prevent accidents
1. make the existing holes smaller
2. add more slices of cheese
3. alert people when holes have aligned

When People Really Are at Fault #

sleep deprivation
under the influence
lack of pre-requisite skill

Design Thinking #

“Designers are trained to discover the real problems.”

The Double Diamond Model of Design #

find the right problem 1.1 discover (diverge) 1.2 define (converge)
find the right solution 2.1 develop (diverge) 2.2 deliver (converge)

“How does the product manager keep the entire team on schedule despite the apparent random and divergent methods of designers? Encourage their free exploration, but hold them to the schedule (and budget) constraints).”

[deadline] “There is nothing like a firm deadline to get creative minds to reach convergence.”

Design Research vs Market Research #

“Design wants to know what people really need and how they actually will use the product or service under consideration.”
=> deep insights on a tiny set of people
“Marketing wants to know what people will buy, which includes learning how they make their purchasing decisions.”
=> large scale quantitative studies
focus groups, surveys, questionnaires, a/b testing
both marketing and design are necessary for a successful product

Idea Generation (or ideation) #

generate numerous ideas
be creative without regard for constraints
question everything

Prototyping #

Testing #

Iteration #

when does the process end?
up to the product manager, who tries make the best possible product in the schedule allotted [deadline] “No matter how much time the design team has been allocated, the final results only seem to appear in the last twenty four hours before the deadline. (It’s like writing: no matter how much time you are given, it’s finished only hours before the deadline.)”
I think that is interesting
like, what is the relationship between deadlines and creativity?
does having a deadline make you more creative?
does having constraints make you more creative?
how can this be used to improve creative processes?

Activity-Centered Design #

focus on activities instead of people
this works because people’s activities tend to be similar across different cultures

goals have three fundamental levels that control activities

be-goals
are the highest most abstract level and govern a person’s being
determine why people act
determine one’s self image
do-goals
determine the plans and actions to be performed for an activity
motor goal
tasks and operations

focus on activities, instead of on tasks (to create better experiences)

In the real world:

“The hardest part of the development of complex products is management: organizing and communicating and synchronizing the many different people, groups, and departmental divisions that are required to make it happen.”
one particularly hard thing is employee turnover (people leaving the project)
“In theory, there is no difference between theory and practice. In practice, there is.”

Don Norman’s Law of Product Development #

The day a product development process starts, it is behind schedule and above budget.

The Stigma Problem #

create products that everyone can use
market them as better products
don’t let your product stigmatize anyone (“inclusive design”)

Complexity is Good; Confusion is Bad #

tasks can be complex
our tools must match the tasks
complexity is ok, as long as it is not confusing
avoid confusion by building a strong conceptual model

Standardization and Technology #

standardization is a confusing process
bad if it happens too early or too late
but essential in many cases that it happens

Deliberately Making Things Too Difficult #

often as a way of keeping people out

Design in the World of Business #

Featuritis: A Deadly Temptation #

existing customers want more features
competing companies add more features
sales decline, because people who want the product already own it

“Most companies compare features with their competition to determine where they are weak, so they can strengthen those area. Wrong, argues Moon. A better strategy is to concentrate on areas where they are stronger and to strengthen them even more. Then focus all marketing and advertisements to point out the strong points. This causes the product to stand our from the mindless her. As for the weaknesses, ignore the irrelevant ones, says Moon. The lesson is simple: don’t follow blindly; focus on strengths, not weaknesses. If the product has real strengths, it can afford to be food enough in the other areas.”

Two Forms of Innovation: Incremental and Radical #

Incremental Innovation => by means of continual testing and refinement
Radical Innovation

Things That Make Us Smart #

technology makes us better (it can do math, remember things, etc)
technology makes us stupider (we can’t function without it)
“Human plus machine is more powerful than either human or machine alone.”
chess example where amateur chess players with regular laptops and a good process beat both chess champions and super computers
“Weak human + machine + better process was superior to a strong computer alone, and superior to strong human + machine + inferior process.”

“The power of the unaided mind is highly overrated. Without external aids, deep, sustained reasoning is difficult. Unaided memory, though, and reasoning are all limited in power. Human intelligence is highly flexible and adaptive, superb at inventing procedures and objects that overcome its own limits. The real powers come from devising external aids that enhance cognitive abilities… It is things that make us smart.”

Needless Features, Needless Models: Good for Business, Bad for the Environment #

consumerism
designing things to break so they need to be replaced

Kudos