1
|
- Week 5
- LBSC 690
- Information Technology
|
2
|
- Exam results
- Mythical person-month (finally!)
- HCI
- Some material from Saul Greenberg:
http://pages.cpsc.ucalgary.ca/~saul/hci_topics/
- Project presentations
|
3
|
- Why is software development different from manufacturing car?
- If it would take one person three months, why does it take four peop=
le
SIX months?
|
4
|
- Sequential constraints
- Communication
- Training
|
5
|
- Rules of thumb
- 1/3 specification
- 1/6 coding
- 1/2 test planning, testing, and fixing!
- Add time for coding to learn as you go, but don’t take time aw=
ay
from the other parts!
- Reread the section on “gutless estimating” if you are
tempted
|
6
|
|
7
|
|
8
|
|
9
|
- A discipline concerned with the
- of interactive computing systems for human use
|
10
|
- Sense low level stimuli
- Recognize patterns
- Reason inductively
- Communicate with multiple channels
- Apply multiple strategies
- Adapt to changes or unexpected events
|
11
|
- Sense stimuli outside human’s range
- Calculate quickly and accurately
- Store large quantities and recall accurately
- Respond rapidly and consistently
- Perform repetitive actions reliably
- Work under heavy load for an extended period
|
12
|
- Humans do what they ar=
e good
at
- Computers do what they=
are
good at
- Strengths of one cover
weakness of the other
|
13
|
- Life critical
- Low error rate first and foremost
- Justifies an enormous design and testing effort
- Custom Commercial
- Office and Home
- Easy learning, high user satisfaction, low cost
- Creative
- User needs assessment is very challenging
|
14
|
- Physical
- Anthropomorphic (height, left handed, etc.)
- Age (mobility, dexterity, etc.)
- Cognitive
- Perceptual
- Personality
- Including cultural factors
|
15
|
|
16
|
- As a user, what do you need to know about a machine in order to inte=
ract
with it effectively?
|
17
|
- How the user thinks the machine works
- What actions can be taken?
- What results are expected from an action?
- How should system output be interpreted?
- Mental models exist at many levels
- Hardware, operating system, and network
- Application programs
- Information resources
|
18
|
|
19
|
- Goals
- What the user is trying to achieve
- Operators
- What capabilities the system provides
- Methods
- How those capabilities can be used
- Selection strategies
- Which method to choose in a specific case
|
20
|
- Text
- Keyboard, optical character recognition
- Speech recognition, handwriting recognition
- Direct manipulation
- 2-D: mouse, trackball, touch pad, touch panel
- 3-D: wand, data glove
- Remote sensing
- Camera, speaker ID, head tracker, eye tracker
|
21
|
- Produces character codes
- ASCII: American Engli=
sh
- Latin-1: European languages
- UNICODE: (nearly) Any language
- Pictographic languages need “entry methods”
- Keyboard shortcuts help with data entry
- Different conventions for standard tasks abound
- VT-100 standard” functions are common
- Differing layouts can inhibit usability
|
22
|
|
23
|
|
24
|
- Match control actions with on-screen behavior
- Use a cursor for visual feedback if needed
- Rotary devices
- Linear devices
- Touch pad, touch screen, iPod shuttle, joystick
- Rate devices
|
25
|
|
26
|
- Visual
- Position/motion, color/contrast, symbols
- Auditory
- Position/motion, tones/volume, speech
- Haptic
- Mechanical, thermal, electrical, kinesthethic
- Olfactory
- Vestibular
|
27
|
- Image display
- Fixed view, movable view, projection
- Acoustic display
- Headphones, speakers, within-ear monitors
- Tactile display
- vibrotactile, pneumatic, piezoelectric
- Force feedback
- dexterous handmaster, joystick, pen
|
28
|
- Inertial Display
- Olfactory Display
- Chemical (requires resupply)
- Locomotive display
- Stationary bicycle, treadmill, ... (trip hazards)
- Temperature Display
|
29
|
- Forming an intention
- “What we want to happen”
- Internal mental characterization of a goal
- May comprise sub-goals (but rarely well planned)
- For example, “write e-mail to grandma”
- Selection of an action
- Review possible actions and select most appropriate
- For example, “use Outlook to compose e-mail”
|
30
|
- Execution of the action
- Carry out the action using the computer
- For example, “double-click Outlook icon”
- Evaluation of the outcome
- Compare results with expectations
- Requires perception, interpretation, and incremental evaluation
- For example, “did Outlook open?”
|
31
|
- Graphical User Interfaces (GUI)
- Direct manipulation (2D, 3D)
- Menus
- Language-based interfaces
- Command line interfaces
- Interactive voice response systems
- Virtual Reality (VR)
- Ubiquitous computing
|
32
|
- Windows
- Icons
- Menus
- Pointing devices
|
33
|
- Windows (and panels)
- Resize, drag, iconify, scroll, destroy
- Selectors
- Menu bars, pulldown lists
- Buttons
- Labeled buttons, radio buttons, checkboxes
- Icons (images)
- Select, open, drag, group
|
34
|
- Select a metaphor
- Desktop, CD player, map, …
- Use icons to represent conceptual objects
- Watch out for cultural differences
- Manipulate those objects with feedback
- Select (left/right/double click), move (drag/drop)
|
35
|
- The perceived and actual fundamental properties
of the object that determine how it could be used
- Appearance indicates how the object should be used
- Chair for sitting
- Table for placing things on
- Knobs for turning
- Slots for inserting things into
- Buttons for pushing
- Complex things may need explaining but
simple things should not
- When simple things need instructions, design has failed
|
36
|
|
37
|
- Limitations of the actions possible perceived from object’s
appearance
- provides people with a range of usage possibilities
|
38
|
|
39
|
- The thing that happens right after an action is assumed by people to=
be
caused by that action
- False causality
- Incorrect effect
- Invoking unfamiliar function just as computer hangs
- Causes “superstitious” behaviors
- Invisible effect
- Command with no apparent result often re-entered repeatedly
- For example, mouse click to raise menu on unresponsive system
|
40
|
|
41
|
- People transfer expectations from similar objects
- Positive: prior learning applies to new situation
- Negative: prior learning conflicts with new situation
|
42
|
|
43
|
- Because a trashcan in Thailand may look like this:
- A Thai user is likely to be confused by this image popular in Apple
interfaces:
- Sun found their email icon problematic for some American urban dwell=
ers
who are unfamiliar with rural mail boxes.
|
44
|
- People learn “idioms” that work in a certain way
- Red means danger
- Green means safe
- Idioms vary in different cultures
- Light switches
- America: down is off
- Britain: down =
is on
- Faucets
- America: counter-clockwise on
- Britain: counter-clockwise off
|
45
|
|
46
|
- Conserve screen space by hiding functions
- Can hierarchically structured
- By application’s logic
- By convention (e.g., where is the print function?)
- Tradeoff between breadth and depth
- Too deep Þ
can become hard to find things
- Too broad Þ
becomes direct manipulation
|
47
|
- What to do when menus become too deep
- Merges keyboard and direct manipulation
- Select menu items by typing part of a word
- After each letter, update the menu
- Once the word is displayed, user can click on it
- Example: Windows help =
index
|
48
|
- Command Entry
- Compact and flexible
- Powerful in the hands of expert users
- Difficult for novices to learn
- Natural Language
- Intuitive and expressive
- Ambiguity makes reliable interpretation difficult
|
49
|
- Informative feedback
- Easy reversal
- User in control
- Anticipatable outcomes
- Explainable results
- Browsable content
- Limited working memory load
- Query context
- Path suspension
- Alternatives for novices and experts
|
50
|
- The structural design of an “information space” to
facilitate access to content
- Consists of at least two components:
- Static design
- Interaction design
|
51
|
- Organizing Principles
- Logical: inherent structure
- Functional: by task
- Demographic: by user
- Take advantage of metaphors
- Organizational: e.g., e-government
- Physical: e.g., online grocery store
- Functional: e.g., cut, paste, etc.
- Visual: e.g., octagon for stop
|
52
|
|
53
|
- Contrast: make different things different
- to bring out dominant elements
- to create dynamism
- Repetition: reuse design throughout the interface
- Alignment: visually connect elements
- Proximity: make effective use of spacing
- to group related and separate unrelated elements
|
54
|
|
55
|
|
56
|
|
57
|
- Chess analogy: a few simple rules that disguise an infinitely complex
game
- The three-part structure
- Openings: many strategies, lots of books about this
- End game: well-defined, well-understood
- Middle game: nebulous, hard to describe
- Information navigation has a similar structure!
- Middle game is underserved
|
58
|
|
59
|
|
60
|
|
61
|
|
62
|
- Drive to content
- Drive to advertisement
- Move up a level
- Move to next in sequence
- Jump to related
|
63
|
- www.philipglass.com
- http://www.michaelkamen.com/
|
64
|
- We respond to sounds without prior focus
- Lack of focus limits simultaneous stimuli
- Absolute amplitude & pitch hard to interpret
- But changes stand out clearly
- Stereo effect provides a sense of direction
- Relative amplitude, phase difference
|
65
|
- Replay of digitized speech clips
- High fidelity, but limited vocabulary
- Speech Synthesis
- Generate spoken output from unrestricted input
- Based on pronunciation rules and lists of exceptions
- Sounds unnatural due to misplaced emphasis
- Prosody-guided speech synthesis
- Use pronunciation of similar words as a guide
|
66
|
- Nonspeech audio output for user interfaces
- Same objectives as graphical output:
- Alert the user to exceptional conditions
- Provide ubiquitous feedback
- Present information
- But different characteristics
- Effective even without focus
- Fairly low resolution
|
67
|
- Need a metaphor
- Clock ticking, alarm bells, keyboard clicks, etc.
- Channel is easily overloaded
- Focus helps manage cognitive load
- Changes are more useful than values
- Pitch, amplitude, position, harmonics, etc.
|
68
|
- Display 2-D images using only sound
- Sweep from left to right every second
- Audible pause and click between sweeps
- Top pixels are high frequency, bottom are low
- Blind users can detect objects and motion
- Time indicates horizontal position
- Pitch indicates vertical position
- Sweep-to-sweep differences indicate motion
|
69
|
- Operate without graphical interfaces
- Hands-free operation (e.g., driving)
- Telephone access
- Built on three technologies
- Speech recognition (input)
- Text-to-speech (output)
- Dialog management (control)
- Example: TellMe (1-800-555-TELL)
|
70
|
- User initiative
- System initiative
- Allows a smaller vocabulary
- Mixed initiative (e.g., barge in)
|
71
|
|
72
|
- Time to learn
- Speed of performance
- Error rate
- Retention over time
- Subjective satisfaction
|
73
|
- Extrinsic vs. intrinsic
- Formative vs. summative
- Human subjects vs. simulated users
- Deductive vs. abductive
|
74
|
- Direct observation
- Evaluator observes users interacting with system
- in lab: user asked to complete pre-determined tasks
- in field: user goes through normal duties
- Validity depends on how contrived the situation is
- Think-aloud
- Users speak their thoughts while doing the task
- May alter the way users do the task
- Controlled user studies
- Users interact with system variants
- Correlate performance with system characteristics
- Control for confounding variables
|
75
|
- HCI design starts with user needs + abilities
- Users have a wide range of
both
- Users must understand their tools
- And these tools can learn about their user!
- Many techniques are available
- Direct manipulation, languages, menus, etc.
- Choosing the right technique is important
- LBSC 795 has this focus
|