Transcript Chapter 2

Chapter 2
The Psychology of Everyday Actions
Chapter 2
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Gulfs of execution/evaluation
Conscious vs. subconscious thought
Declarative vs. procedural knowledge
Emotional design
Visceral/behavioral/reflective activity/responses
People as storytellers/causation/blame
Failure and blame vs. breakdowns and recovery
Designing for human activity and variation
Abstraction of User Interaction
• What is going on in computer-human
interaction?
• How do users decide what to do to achieve
their goals?
The gulfs
• The ‘gulfs’ explicate the gaps that exist between the
user and the interface
• The gulf of execution
– the distance from the user to the physical system
• The gulf of evaluation
– the distance from the physical system to the user
• Need to bridge the gulfs in order to reduce the
cognitive effort required to perform a task
Norman’s (1986) Theory of action
• Proposes 7 stages of an activity
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Establish a goal
Form an intention
Specify an action sequence
Execute an action
Perceive the system state
Interpret the state
Evaluate the system state with respect to the goals and
intentions
An example: reading breaking news on
the web
(i)
Set goal to find out about breaking news
decide on news website
(ii)
Form an intention
check out BBC website
(iii) Specify what to do
move cursor to link on browser
(iv) Execute action sequence
click on mouse button
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Check what happens at the interface
see a new page pop up on the screen
(vi) Interpret it
read that it is the BBC website
(vii) Evaluate it with respect to the goal
read breaking news
How realistic?
• Human activity does not proceed in such an orderly
and sequential manner
• More usual for stages to be missed, repeated or out
of order
• Do not always have a clear goal in mind but react to
the world
• Theory is only approximation of what happens and is
greatly simplified
• Help designers think about how to help users
monitor their actions
Conscious vs. Unconscious Thought
• Upon initial use of a new item almost all
activity requires conscious thought
• Over time, people no longer have to think
about many actions (e.g. typing)
– Frees conscious mind to work on higher-level
items
– But removes the ability for users to describe their
processes
Alternative Representations of
Knowledge
• Stored as data
– Memory of information
– Can think of databases or indexed document
stores
– Examples of data you know as a CS expert?
• Stored as process
– Memory of processes for determining information
– Can think of production rules,
– Examples of process you know as a CS expert?
How Much Knowledge?
• A professional’s knowledge is adequate when she knows
about as much as other professionals in her domain.
– Time available to acquiring and maintaining knowledge will affect limit
for large domains
• Describing expertise
– ~50,000 chunks across disciplines, or 10 years of learning
• When a domain exceeds this
– It will increase use of externalized information stores
– It will divide into subfields (specialize)
• Science proceeds through producing new knowledge and
compressing old through more general theories
Affective (Emotional) Design
• HCI has traditionally been about designing efficient and
effective systems
• Now more about how to design interactive systems that make
people respond in certain ways
– e.g. to be happy, to be trusting, to learn, to be motivated
• Color, icons, sounds, graphical elements and animations are
used to make the ‘look and feel’ of an interface appealing
– Conveys an emotional state
• In turn this can affect the usability of an interface
– People are prepared to put up with certain aspects of an interface
(e.g. slow download rate) if the end result is appealing and aesthetic
Example: Friendly interfaces
• Microsoft pioneered friendly interfaces for technophobes
- ‘At home with Bob’ software
• 3D metaphors based
on familiar places
(e.g. living rooms)
• Agents in the guise
of pets (e.g. bunny,
dog) were included
to talk to the user
– Make users feel
more at ease and
comfortable
Responses and Actions
• Visceral
– Unconscious, almost hard-wired response
• Behavioral
– Result of unconscious, learned knowledge
• Reflection
– Conscious reaction
Slight Detour: Anthropomorphism
• Attributing human-like qualities to inanimate
objects (e.g. cars, computers)
• Well known phenomenon in advertising
– Dancing butter, drinks, breakfast cereals
• Much exploited in human-computer interaction
– Make user experience more enjoyable, more
motivating, make people feel at ease, reduce anxiety
Which do you prefer?
1. As a welcome message
• “Hello Chris! Nice to see you again. Welcome
back. Now what were we doing last time? Oh
yes, exercise 5. Let’s start again.”
• “User 24, commence exercise 5.”
Which do you prefer?
2. Feedback when get something wrong
1. “Now Chris, that’s not right. You can do
better than that.Try again.”
2. “Incorrect. Try again.”
Is there a difference as to what you prefer
depending on type of message? Why?
Evidence to support anthropomorphism
• Reeves and Naas (1996) found that computers
that flatter and praise users in education software
programs -> positive impact on them
“Your question makes an important and useful
distinction. Great job!”
• Students were more willing to continue with
exercises with this kind of feedback
Criticism of anthropomorphism
• Deceptive, make people feel anxious, inferior or stupid
• People tend not to like screen characters that wave their
fingers at the user & say:
– Now Chris, that’s not right. You can do better than that.Try
again.”
• Many prefer the more impersonal:
– “Incorrect. Try again.”
• Studies have shown that personalized feedback is considered
to be less honest and makes users feel less responsible for
their actions (e.g. Quintanar, 1982)
Virtual characters
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Increasingly appearing on our screens
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Web agents, characters in videogames, learning
companions, wizards, pets, newsreaders, popstars
Provides a persona that is welcoming, has
personality and makes user feel involved with
them
Clippy
• Why was Clippy disliked
by so many?
• Was it annoying,
distracting,
patronising or other?
• What sort of user
liked Clippy?
Disadvantages of Interface Agents
• Lead people into false sense of belief, enticing
them to confide personal secrets with chatterbots
(e.g. Alice)
• Annoying and frustrating
– e.g. Clippy
• Not trustworthy
– virtual shop assistants?
Error, Failure, Blame
• Causation – people are used to looking for
causes in the world around them
– They assign causes when none exist
– They wrongly accept blame for similar reasons
• Interfaces need to be designed for unexpected
behaviors
• Human-human interaction proceeds through a
process of:
– action -> breakdown -> recovery -> action …
Error messages
“The application Word Wonder has unexpectedly quit due to a
type 2 error.”
Why not instead:
“the application has expectedly quit due to poor coding in the
operating system”
• Shneiderman’s guidelines for error messages include:
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avoid using terms like FATAL, INVALID, BAD
Audio warnings
Avoid UPPERCASE and long code numbers
Messages should be precise rather than vague
Provide context-sensitive help
Should computers say they’re sorry?
• Reeves and Naas (1996) argue that computers should be made
to apologize
– Should emulate human etiquette
• Would users be as forgiving of computers saying sorry as people
are of each other when saying sorry?
• How sincere would they think the computer was being? For
example, after a system crash:
– “I’m really sorry I crashed. I’ll try not to do it again”
• How else should computers communicate with users?
Breakdowns and Recovery
• Donald Schoen says design (and other human activity)
proceeds through a series of
– Unselfconscious action
– Breakdown
– Reflection in action
• Is this how we let our unconscious perform activities
freeing our conscious self for other efforts?
– Expectation is that there will be breakdowns
– Breakdowns caused by unexpected circumstances or
unexpected outcomes
• Learning through breakdowns: “To Engineer is Human”
Universal Design & Accessibility
• Not all users are the same. Some examples:
– Visually impaired or blind (~2% in US)
– Color blindness (7% of men, 0.4% of women in US)
– Moderate to severe hearing loss (10% of
population, maybe >40% in senior population)
– Essential tremors (1-5%)
• All of these have implications for computer
use
Chapter 2
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Gulfs of execution/evaluation
Conscious vs. subconscious thought
Declarative vs. procedural knowledge
Emotional design
Visceral/behavioral/reflective activity/responses
People as storytellers/causation/blame
Failure and blame vs. breakdowns and recovery
Designing for human activity and variation
Compare these Visions
• Apple’s “Knowledge Navigator”
– https://www.youtube.com/watch?v=9bjve67p33E
• Sun’s “Starfire: A Vision of Future Computing”
– https://www.youtube.com/watch?v=NKJNxgZyVo0