Human%20Abilities:%20Cognition - PowerPoint PPT Presentation

View by Category
About This Presentation
Title:

Human%20Abilities:%20Cognition

Description:

Subway. Precinct. Tiles. Typist. Income. Saucer. Paper-clip ... pie menu (bigger targets & less distance) Today. Sunday. Monday. Tuesday. Wednesday. Thursday ... – PowerPoint PPT presentation

Number of Views:35
Avg rating:3.0/5.0
Slides: 120
Provided by: johnke8
Learn more at: http://staffweb.itsligo.ie
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Human%20Abilities:%20Cognition


1
Human Abilities Cognition
  • James Landay
  • John Kelleher

2
Plain English campaign!
3
Outline
  • Human visual system
  • Guidelines for design
  • Models of human performance (MHP)
  • Memory

4
Models of the User
  • Model Human Processor
  • Our Model

Cognitive System
Perceptual System
Memory
I/O
Motor System
CPU
5
Human I/O Channels
  • Input via the senses
  • Sight
  • Hearing
  • Touch
  • Taste
  • Smell
  • Output via motor control
  • Limbs (feet?)
  • Fingers
  • Eyes
  • Head
  • Voice

6
Why Model Human Performance?
  • To test understanding
  • To predict influence of new technology

7
The Model Human Processor
  • Developed by Card, Moran, Newell (83)
  • based on empirical data

Perceptual Processor
8
Model Human Processor(Card, Moran Newell)
9
Model Human Processor Components
  • Cycle times
  • Decay Rates
  • Storage Capacities
  • Coding/Representation Schemes

10
Perceptual (Sensory) Memories
  • Area of memory that deals with information from
    the senses
  • Perceptual memories are highly volatile
    information stores
  • Information flows from perceptual (sensory)
    memories into Working Memory
  • Perceptual memories decay almost immediately and
    are replaced by new, incoming information
  • Selection of stimuli governed by level of arousal

11
What is This?
12
Parameters of Perceptual Memories
  • Visual (Iconic) Memory
  • Coding Scheme Physical analogs
  • Capacity 17 letters
  • Decay Rate 200ms
  • Auditory (Echoic) Memory
  • Coding Scheme Physical analogs
  • Capacity 5 letters
  • Decay Rate 1500 ms
  • Buffers for stimuli

13
Perceptual Processor
  • The speed of the perceptual processor is about
    100ms per cycle
  • Light blinks appearing within 100ms look like a
    single brighter light
  • e.g. frames of a film seen as continuous fluid
    scene reflects some processing by sensory
    processor.
  • Light blinks in two locations within 100ms look
    like motion of a single light
  • Auditory clicks occurring within 100ms sound like
    one louder tone
  • Also, sensory memory for hearing more durable
    than others
  • Multiple taps occurring within 100ms feel like
    one tap of greater pressure

14
Working Memory(Short-term Memory)
  • Working Memory is a temporary information store.
  • Working Memory receives information from
    Perceptual Memories and LTM
  • Working Memory can influence LTM
  • Information in Working Memory is often recoded
  • e.g. Visual information is rehearsed as auditory
  • Chunking is already happening
  • People have some control over Working Memory
  • Rehearsal
  • Attention

15
Memory
  • Working memory (short term)
  • small capacity (7 2 chunks)
  • 6174591765 vs. (617) 459-1765
  • AIBIBMEMC vs. AIB IBM EMC
  • Chunking
  • Grouping together information into sections that
    make sense to the individual and seen as entities
    by that individual
  • E.g. master chess players (but only for legal
    positions)
  • rapid access ( 70ms) decay (200 ms)
  • pass to LTM after a few seconds

16
Chunking
1 chunk Recoded to image
3 chunks Recoded to words
9 chunks Recoded to letters
Perceptual memory
17
Primacy and Recency Effects
List 1 List 2 List 3
Barrier Babies File
Firearms Sofa Heart
Scarf Lobby Scarecrow
Newspaper Clock Stylus
Sea-shell Polish Maggot
Tomato Lintels Rug
Apologies Dog Flea
Table Dolls-house Ball-pen
Plant Oasis Jamboree
Chemist Festival Neptune
Identity Gnat Magnum
Percolator Curtains Paper-clip
Saucer Income Typist
Tiles Precinct Subway
Directory Argument Accident
18
Primacy Recency Effect
  • Free recall
  • Recalling lists in any order
  • Primacy effect
  • Tendency for first words on list to be commonly
    recalled
  • Recency effect
  • Tendency for last words on list to be commonly
    recalled

19
Fun with Working Memory
25439762608
456 295 1413
HEC ATR ANU PTH ETR EET
20
Interference affects recency
List 1 List 2 Then do
Aubergine Rescue 1
Chickenpox Gravestone 6
Elephant Flower -4
Telephone Fountain 9
Pendant Statue -2
Egg Fool 8
Melancholy Aphid -9
Cheese Surprise -6
Mug Printer -2
Nymph Cenotaph
Dinghy Dog basket
Tray Magnet
Mole Lawn
Tram Pram
Macabre Sandwich
21
Memory
  • Extent to which new material can be remembered
    depends on its meaningfulness
  • Levels (Depth) of processing theory (Craik
    Lockhart, 1972)
  • Info processed at different levels
  • e.g., processing physical features of a word such
    as its sound
  • Deep, semantical analysis
  • Depth of processing determines how well
    remembered
  • Elaborative (effortful process) vs. maintenance
    rehearsal
  • Closure
  • Feeling of relief when task successfully
    completed
  • E.g. successful logon
  • Important to permit processes to be chunked in
    memory
  • E.g. avoid traversing between windows within an
    application

22
Depth of Processing (shallow)
  • flame
  • patch
  • sonic
  • bless
  • avarice
  • pears
  • spade
  • bliss
  • forth
  • peels
  • speed
  • avoid
  • freak
  • pints
  • rare
  • blush
  • slow
  • pluck

23
Depth of Processing (deep)
  • spoon
  • shares
  • glass
  • ports
  • spray
  • boots
  • goose
  • prize
  • steam
  • runner
  • grass
  • pint
  • stink
  • bride
  • green
  • queen
  • story
  • brown

24
Memory
  • Factors that determine meaningfulness
  • Familiarity of an item, and the frequency with
    which a word occurs in everyday language
  • Familiar Door, read, stop
  • Unfamiliar compile, substitute, scan
  • Its associated imagery, the ability with which
    the word can elicit images in ones mind
  • Ride, sleep, eat
  • Begin, increase, evaluate
  • Information best recalled if in situ
  • E.g. Diver education (Baddeley)

25
Improving memory
  • Method of Loci
  • Visualising familiar route associated items at
    particular locations long route
  • Peg-word method
  • Associate items with rhyming words numbers
  • Creating a narrative
  • Create story or song linking concepts together
  • Creating acronyms
  • e.g. A.B.C. of First Aid

26
Implications for UI design
  • Items that need to be remembered at the interface
    should be as meaningful as possible
  • Problems with command line interfaces
  • e.g., command names and icons should be selected
    according to meaningfulness
  • cp vs. copy
  • Words that represent visible objects easiest to
    recall
  • Memory best facilitated by relaxed user
  • Ask only relevant material
  • Or provide user with reason for action
  • Asking for non-sensible information

27
Peg Word Memory Aid
  • 1 bun
  • 2 shoe
  • 3 tree
  • 4 door
  • 5 hive
  • 6 sticks
  • 7 heaven
  • 8 gate
  • 9 wine
  • 10 hen

28
(No Transcript)
29
Memory Factors
  • Total time hypothesis
  • Distribution of Practice Effect
  • Listen
  • The engines roared above the noise of the crowd.
    Even in the blistering heat people rose to their
    feet and waved their hands in excitement. The
    flag fell and they were off. Within seconds the
    car had pulled away from the pack and was
    careering round the bend at a desperate pace. Its
    wheels momentarily left the ground as it
    cornered. Coming down the straight the sun
    glinted on its shimmering paint. The driver
    gripped the wheel with fierce concentration.
    Sweat lay in fine drops on its brow.
  • People prone to embellishment and localisation
    of facts.

30
Long-Term Memory (LTM)
  • Long-term memory stores everything that we know
    -- facts, experience, knowledge, procedural rules
    of behavior.
  • LTM has huge capacity.
  • LTM has a relatively slow access compared to
    short-term memory.
  • activation is process of recall to WM
  • Only encode the important information
  • Forgetting also occurs slowly.
  • Causes for forgetting
  • 1) Never stored encoding failed
  • 2) Gone from storage storage failed (??)
  • 3) Cant get out of storage retrieval failed
  • Interference model of forgetting
  • one item inhibits the retrieval of another
  • proactive interference (3)
  • retroactive interference (3 2)

31
Pennies Example
32
Long-term Memory
  • Long-term memory works by semantics and by
    association.

33
Parameters of LTM
  • Semantic network (encoded in terms of meaning and
    relationships).
  • Related associations, images, and past
    experiences
  • How knowledge is encoded makes a difference in
    how knowledge is recalled
  • Recognition is much easier than recall
  • (DOS prompt vs. Mac user interface)
  • Coding Scheme Semantic
  • Capacity Unlimited
  • Decay Rate None
  • However, recall from LTM is affected by encoding
    specificity and retrieval cues

34
Encoding Specificity
  • Specific encoding operations performed on what
    is perceived determine what is stored, and what
    is stored determines what retrieval cues are
    effective in providing access to what is stored.
  • -- Card, Moran, Newell (1983)
  • This is a fancy way of saying that the encoding
    context matters

35
Discrimination Principle
  • The difficulty of memory retrieval is determined
    by the candidates that exist in the memory
    relative to the retrieval cues.
  • -- Card, Moran, Newell (1983)

36
Cognitive Processor
  • The recognize-act cycleis the basic quantum of
    cognitive processing. (CMN, 1983)
  • In each cycle, the contents of Working Memory
    activate something in LTM which in turn modifies
    the contents of Working Memory
  • Cycle time is 70ms

37
Motor Processor
  • Draw parallel lines (approx. 4cm apart)
  • For a duration of 5 seconds
  • Draw a zig-zag line back and forth between the
    lines working left to right
  • The basic motor cycle time is 70ms
  • Move pen back and forth between two lines
  • 71 reversals in 5 sec, or 70ms/reversal
  • forgetting anything?

38
Putting It All Together
  • True reaction time
  • 1 perceptual cycle 1 cognitive cycle 1 motor
    cycle
  • 100ms70ms70ms 240ms
  • Some studies include additional cognitive step
  • Raises total by 70ms to 340ms

39
Principles of Operation (cont.)
  • Fitts Law
  • moving hand is a series of microcorrections
  • correction takes Tp Tc Tm 240 msec
  • time Tpos to move the hand to target size S which
    is distance D away is given by
  • Tpos a b log2 (D/S 1)
  • summary
  • time to move the hand depends only on the
    relative precision required

40
Fitts Law Example
  • Which will be faster on average?
  • pie menu (bigger targets less distance)

41
Perception
  • Stimuli that occur within one PP cycle fuse into
    a single concept
  • frame rate needed for movies to look real?
  • time for 1 frame lt Tp (100 msec) -gt 10
    frame/sec.
  • Perceptual causality
  • two distinct stimuli can fuse if the first event
    appears to cause the other
  • events must occur in the same cycle

42
Perceptual Causality
  • How soon must red ball move after cue ball
    collides with it?
  • must move in lt Tp (100 msec)

43
What is missing from MHP?
  • Haptic memory
  • for touch
  • Moving from sensory memory to WM
  • attention filters stimuli passes to WM
  • Moving from WM to LTM
  • elaboration

44
Cognitive Processes
  • Controlled
  • limited capacity require attention and conscious
    control
  • easier to change
  • Automatic
  • Activities we carry out that have become
    automated
  • Reading, writing, speaking in native language
    (others?)
  • We dont have to attend to (think about) what we
    are doing.

45
Automatic Processing
  • The more we practice, the more our performance
    improves to the point that we become skilled, and
    performance is automatic
  • Characteristics
  • fast,
  • demanding minimal attention, therefore
  • doesnt interfere with other activities
  • unavailable to consciousness
  • hard to change once learned

46
Effect on UI design decisions
  • Interactions that have become automatic are
    difficult to unlearn
  • Microsofts approach to WordPerfect domination
  • Consistency across versions, tools can help avoid
    this problem
  • Microsoft Office critical mass of usage stiffles
    StarOffice

47
Stroop Effect
  • Example of automatic behaviour
  • Volunteer
  • Start saying colors you see in list of words
  • when slide comes up
  • as fast as you can
  • Say done when finished
  • Everyone else time it

48
Say the colour of these words
  • Paper
  • Home
  • Back
  • Schedule
  • Page
  • Change

49
Simple Experiment
  • Do it again
  • Say done when finished

50
Now do it again
  • Blue
  • Red
  • Black
  • White
  • Green
  • Yellow

51
Importance of Context
  • Bottom-up perception uses features of stimulus
  • Top-down perception uses context (and prior
    knowledge)
  • Temporal (for hearing) what we heard before or
    after stimulus
  • Spatial (for visual) whats around the stimulus
    (as below)
  • draws on long-term memory

52
Gestalt Laws of Grouping
  • German Psychologists
  • Primary purpose of visual system is recognition
    of objects from basic visual elements
  • Objects seen as more than a sum of the parts
  • When elements are arranged in groups that define
    an object, we tend to see the object and not the
    elements.
  • e.g. ascii art

53
Gestalt Principles
Similarity
Continuity
Symmetry
54
Law of Proximity
  • Things that are relatively close to one another
    tend to be grouped together.

55
Laws of Similarity
  • Items that look similar will be seen as parts of
    the same form

56
Law of good continuation
  • Objects arranged in either a straight line or a
    smooth curve tend to be seen as a unit.

57
Law of Closure
  • Innate tendency to perceive incomplete objects as
    complete and to close or fill gaps and to
    perceive asymmetric stimuli as symmetric

58
Law of common fate
  • The law of common fate leads us to group together
    objects that move in the same direction. In the
    following illustration, imagine that three of the
    balls are moving in one direction, and two of the
    balls are moving in the opposite direction. If
    you saw these in actual motion, you would
    mentally group the balls that moved in thesame
    direction. Because of this principle, we often
    see flocks of birds or schools of fish as one
    unit.

59
Attention
  • Everyone knows what attention is. It is the
    taking possession of mind, in clear and vivid
    form, of one out of what seem several
    simultaneously possible objects or trains of
    thought It requires withdrawal from some things
    in order to deal effectively with others.
  • W. James, 1890

60
cocktail party phenomenon
  • Ability to focus on one activity, while tuning
    out others
  • can be distracted from one task if attention
    called to another

61
Attention
  • Can design interfaces to help users find
    information they need
  • Can structure interface so it is easy to navigate
  • Not too much information, nor too little
  • Rather than arbitrarily presenting information
  • use groupings
  • order in meaningful way
  • See Gestalt laws of perceptual grouping

62
Attention
  • Manner in which we deploy our attention has a
    tremendous bearing on how effectively we can
    interact with a system
  • Focused attention
  • Ability to attend to one event from what amounts
    to a mass of competing stimuli in the environment
  • Divided attention
  • Ability to attend to more than one stimuli at a
    time
  • Cocktail party phenomenon
  • Voluntary or involuntary

63
Implications for Design
  • Users are prone to distraction
  • On returning to suspended activity
  • May forget where they left off
  • May forget whether they completed the task or not
  • Forgetting to put salt French fries, or doing it
    twice
  • Answer cognitive aids
  • Reminders or external representations intended to
    gain attention at a time relevant to the task
    that needs to be performed.
  • E.g., status area indicating task status, coffee
    cup on flaps

64
Attention
  • Other techniques for presenting information to
    guide attention
  • Spatial and temporal cues
  • Example
  • Color
  • Alerting techniques
  • Flashing and reverse video
  • Audio warnings

65
Attention
  • Windows are a useful way to partition the screen
    into discrete or overlapping sections
  • enable different types of information to be
    separated, provides meaningful groupings
  • e.g., word processor
  • Text area
  • Footnote area
  • Command area

66
Implications for Design
  • Info which needs immediate attention should
    always be displayed in a prominent place (error
    and warning messages)

67
Implications for Design
  • Less urgent info should be allocated to a less
    prominent but specific areas of the screen so
    that the user will know where to look when this
    information is required.

68
Implications for Design
  • Information that is not needed very often should
    not be displayed but should be made available on
    request.

69
Goals of Representation Aiding
  • Turn a cognitive task into a perceptual task.
  • Offload human working memory onto an external
    representation.
  • Map relevant constraints in the domain onto
    relevant representational properties.
  • Encourage people to develop a correct mental
    model

70
Implications for Design
  • You have to understand the persons task!!
  • You have to understand the domain!
  • People have cognitive constraints and abilities
  • The domain imposes constraints
  • Map those together into a design that represents
    domain constraints in a way that people can best
    perceive/understand.

71
Ventilator Management Example
  • Practitioners Intensive Care Unit specialists
  • Task To evaluate whether a patient is recovering
    his/her own breathing over time
  • Ventilator vs. Patient Rate of breathing, depth
    of breathing

72
Todays displays
  • Typical process control displays with tables and
    tables of LabelValue parameters
  • Every variable thats measured by the patient is
    displayed on the screen, (single sensor single
    indicator) e.g.
  • Ventilator Patient
  • Rate of breathing 10 Rate of breathing 2
  • Depth of breathing 5 Depth of breathing 6
  • Difficult to get status at a glance, to judge
    whether patient is improving or not.

73
Novel Display(Volume Rectangles)
Patient
Ventilator
rate
volume
(Cole and Stewart, 1994)
74
A series of volume rectangles
Ventilator Patient at time t1
Ventilator Patient at time t21
The patient is clearly doing more of his/her own
breathing over time.
75
Evaluation of Novel Display
  • Physicians had perfect performance in judging
    whether patients were getting better or worse
    over time.
  • Furthermore, the physicians judgments were
    significantly faster using the novel volume
    rectangle display than using the familiar table
    of numbers currently used in practice.

76
Recognition over Recall
  • Recall
  • info reproduced from memory
  • e.g., command name semantics
  • Recognition
  • presentation of info provides knowledge that info
    has been seen before
  • e.g., command in menu reminds you of semantics
  • easier because of cues to retrieval
  • cue can be anything related to item or situation
    where it was learned
  • example giving hints
  • other examples in software?
  • icons, labels, menu names, etc.

77
Knowledge in the Head and in the World
  • Knowledge in the world
  • is the information in the environment
  • Knowledge in the head
  • is the information that is stored in memory
  • Most of the time we need to combine the two types
    knowledge to operate things.

78
Knowledge in the World/Head
79
Because ...
  • Not all of the knowledge required for precise
    behavior has to be in the head
  • partly in the head
  • partly in the world
  • partly in the constraints
  • E.g. clipboard and spike

80
Also because ...
  • We can recognize material far more easily than we
    can recall it.
  • Knowledge in the world lets people recognize
    facts or things.
  • E.g. road signs
  • Knowledge in the head requires recall.

81
AIB 24-Hour Online Banking
  • User logs on to
  • Check balances
  • Move funds
  • Cancel cheques
  • AIB offers TransactOnline to
  • Provide one-time credit card numbers tied to
    users account

82
Opening Logon Screen
83
Further Validation Screen
84
TransactOnline SignOn
85
(No Transcript)
86
(No Transcript)
87
(No Transcript)
88
(No Transcript)
89
Further ReadingVision and Cognition
  • Books
  • The Psychology Of Human-Computer Interaction, by
    Card, Moran, Newell, Erlbaum, 1983
  • Human-Computer Interaction, by Dix, Finlay,
    Abowd, and Beale, 1998.
  • Perception, Irvin Rock, 1995.
  • Articles
  • Using Color Effectively (or Peacocks Can't Fly)
    by Lawrence J. Najjar, IBM TR52.0018, January,
    1990, http//mime1.marc.gatech.edu/mime/papers/col
    orTR.html

90
Extra Slides
91
Vision (1/3)
  • Two aspects physical receptor subsequent
    perception processing
  • Photoreceptors
  • Rods (120 m., light sensitive, can be saturated,
    concentrated on edges of retina, poor visual
    acuity).
  • Cones (6 m., less light sensitive, colour
    perceptors, concentrated on fovea, blind spot).
  • Ganglion cells
  • specialised nerve cellsX-cells (fovea centred,
    pattern detection)Y-cells (distributed on
    retina, movement detection)
  • Size Depth Perception
  • Visual angle (larger angle at same distance
    implies larger object)
  • Visual acuity (fine detail perception)
  • Law of size constancy
  • relies on cues - overlapping objects, size and
    height of object, familiarity with object.

92
Vision (2/3)
  • Brightness
  • Subjective quantity affected by luminance
    contrast
  • visual system adjusts to perceive in differing
    lighting rods/cones
  • visual acuity increases with luminance as does
    flicker
  • Colour
  • 3 components (hue, intensity, saturation)
  • Hue determined by wavelength
  • Blues short, greens medium and reds long
    wavelength.
  • Intensity is brightness of colour
  • Saturation is amount of whiteness in the colour
    (washed-out affect)
  • 3 types of cones sensitive to RGB (fewest cones
    for blue)
  • colour blindness
  • Visual Processing
  • Movement of retina changes in luminance are
    perceived as constant
  • Ability to interpret and anticipate images is
    vital - easily fooled, however.
  • Muller-Lyer illusion, Ponzo illusion.

93
Touch
  • Secondary source of information
  • Crucial to people with disabilities
  • Touch is not localised
  • 3 Types of sensory receptor
  • Thermoreceptors - heat and cold
  • Nociceptors - intense pressure, heat and pain
  • Mechanoreceptors - pressure
  • rapidly adapting
  • slowly adapting
  • two-point threshold test
  • Kinesthesis
  • awareness of position of body and limbs
  • three types
  • rapidly adapting (moving of limb)
  • slowly adapting (movement and static position)
  • positional receptors (static position only)

94
Engineering Models of Human Performance
  • Predictive
  • Quantitative
  • time to perform
  • time to learn
  • number and type of errors
  • time to recover from errors
  • Learnable and usable by systems designers
  • Usefully approximate

95
LTM Processes
  • Remembering or Storing
  • Repeat rehearsal or exposure to information aids
    remembering
  • Ebbinghauss Total time hypothesis
  • Baddeleys Distribution of practice effect.
  • Factors boosting memorability familiarity,
    concrete images, meaningfulness, structure.
  • Forgetting (2 Theories)
  • Decay
  • Ebbinghaus - information decays logarithmically
  • Josts Law - Older memories more durable
  • Interference Losses
  • Retroactive interference (newer knowledge
    inhibits older)
  • Proactive inhibition (older knowledge reappears)
  • Non-emotive words more durable than emotive words
    (exhibited in nostalgia of good old days)
  • Difficulty in proving forgetfulness. Associations
    need to be exercised.
  • Retrieval
  • Recall and Recognition
  • Categorisation, vivid imagery and familiarity aid
    retrieval.

96
Reasoning
  • Deductive Reasoning
  • Derives the logically necessary conclusion from
    the given premises.
  • Some people are babies, some babies cry. Some
    people cry?
  • Truth and validity clash.
  • Bring world knowledge into reasoning process to
    facilitate shortcuts.
  • Inductive Reasoning
  • Generalising from cases we have seen to infer
    information about cases we have not seen
  • Every elephant we have seen has a trunk
    therefore we infer all elephants have trunks
  • Unreliable inference
  • Cannot be proved only disproved by producing a
    trunkless elephant.
  • Wasons Cards. Need to disprove statement not add
    more proof.
  • Abductive Reasoning
  • Reasoning from a fact to the action or state that
    caused it.
  • Used to derive explanations from the events we
    observe.
  • Often unreliable though we hold such
    explanations until they can be disproven.

97
More Slides from
  • Washington State University
  • School of EECS
  • CptS 443 - Human Computer Interaction

98
Long Term Memory
  • The Human World-Wide Web
  • Two types
  • episodic - events, organized temporally
  • semantic - facts, organized associatively
  • Representations
  • semantic nets
  • frames
  • scripts

99
Semantic Network
university
WSU
100
Frames
  • Extends semantic nets to include structured
    hierarchical information

University Fixed type of school Default has
colleges Variable public/private
WSU Fixed type of University Default
public Variable campus
101
Scripts
  • Stereotypical information
  • Entry conditions need job, have money
  • Result educated, less money
  • Props books, schedule, new car
  • Roles instructor talks, students listen
  • Scenes classroom, dorm
  • Tracks internships, apprenticeships

102
Processes
  • How does information get from short term memory
    into long term memory?
  • Total time hypothesis - hit the books
  • Distribution of practice effect - dont cram
  • Meaning - concrete better than abstract
  • faith age cold tenet quiet logic idea value past
  • boat tree cat child rug plate gun flame head
  • Structure, familiarity and concreteness

103
How We Forget
  • Decay
  • Logarithmically - forget most early
  • Josts Law - if two equally strong memories at a
    given time, then the older is more durable.
  • Interference
  • retroactive interference - old phone number
  • proactive inhibition - driving to the old house
  • emotion - good old days, forget the mundane

104
Information Retrieval
  • How do we recall details?
  • Categorization
  • Visualization

1 bun 2 shoe 3 tree 4 door 5 hive
6 sticks 7 heaven 8 gate 9 wine 10 hen
105
Real Intelligence
  • How is information processed and manipulated?
  • Animals - receive and store info, but do not
    process it as well as humans
  • Computers - receive and store info better then
    humans, but do not process it as well as humans

106
Human Intelligence
  • Humans use information to
  • Reason solve problems
  • Even if the info is partially missing or
    completely absent!
  • Human thought is
  • conscious self-aware
  • capable of imagination

107
Reasoning
  • Inferring missing information
  • Deductive - conclusions
  • Inductive - generalizations
  • Abductive - suppositions

108
Deductive Reasoning
  • If A then B
  • A. Therefore B
  • not B, therefore not A.
  • The phone rings when Im in the shower
  • If Im in the shower, then the phone rings
  • When the phone rings, take a shower
  • No shower? Phone doesnt ring.

109
Inductive Reasoning
  • Specific A has property B then all A is B
  • Elephants have trunks
  • Computers are slow
  • Classes are exciting
  • Students hand homework in on time
  • WHETS is fun
  • Geeks are rich

110
Wason Cards
  • If a card has a vowel on one side it has an even
    number on the other. True or False?

4
E
7
K
111
Abductive Reasoning
  • From fact to the action that caused it
  • Totalled car
  • Black eye
  • 4.0 GPA
  • Smile/frown
  • Core dump
  • Phone ring

112
Problem Solving
  • Using knowledge to find a solution
  • Gestalt theory
  • Problem space theory
  • Analogy

113
Gestalt Theory
  • Finding new solutions
  • Reproductive problem solving
  • Learned behavior, trial and error
  • Behavioralist
  • Fixation
  • Productive problem solving
  • Invention, innovation, insight
  • Pendulum problem

114
Problem Space Theory
  • Mapping out a solution step by step
  • Problem states, goal state, current state
  • Legal state transition operators
  • Heuristics, e.g. means-ends analysis
  • Examples
  • Games 15 puzzle, chess
  • Tasks Setting the VCR clock
  • Life (emphasis on legal)

115
Analogy
  • Applying one solution to a different problem
  • Analogical mapping
  • Purely productive reasoning is hard (10)
  • Drawing analogies is easier (80)
  • Existing solution semantically close to problem
    domain

116
Skill Acquisition
  • Solving problems that are not completely new
  • e.g. Chess
  • Same goal (different goal states)
  • Same transitions
  • Different skills
  • Problem groups
  • novices group problems superficially
  • experts group problems conceptually

117
ACT Skill Acquisition Model
  • How is skill acquired?

General rules
Proceduralization
Specific rules
Generalization
Tuned rules
118
Errors
  • How do we make mistakes?
  • Slips - change in context of skill
  • Mental models - incorrect interpretation of the
    evidence

119
Design
  • How do we use what we know about humans to make
    better user interfaces?
  • Guidelines
  • Models
  • Evaluation
About PowerShow.com