2D Multimedia Authoring

1
2D Multimedia Authoring

• Interaction Styles

2
Lecture Overview

• Linguistic
• Command-line interaction
• Text-based natural language
• Key-modal
• Question-and-answer
• Function-key interactiion
• Menu-based interaction
• Hypermedia
• Direct manipulation
• Forms
• Graphical direct manipulation

3
LinguisticCommand Languages

• Grammar
• Verb first, then nouns and adjectives i.e. action
  - object
• Can be fastest entry / retrieval of info
• Usually offers high level of functionality
• Main drawbacks learnability and retainability
• Strategies
• Simple Command List e.g. VI
• Command Plus Arguments e.g copy filea fileb
• Commands plus options and arguments
  e.g Print/queuelocalprinter/copies3
  my.dat

4
Linguistic Natural Language

• Convenient
• Great expressive power
• BUT problem of AMBIGUITY in unconstrained natural
  language
• The house was built by the river
• Scope Grave financial and other hardship
• Knowledge of context often essential
• Wartime report German push bottles up allies
• Cleaning lady earns 70, MD earns 80,000
• Current implementations of NL interfaces operate
  in restricted domains
• e.g. Database access

5
Key-modalQuestion and Answer

• Questions, one at a time, in text form
• Suited to short data entries e.g. wizards
• Limited variation in sequence
• User needs little training
• Limited support for correcting errors in previous
  entries
• Generally slow to use

6
Key-modal Function-Key Interaction

• Suit use in public places e.g. ATM
• Usually strict sequences of operation - can model
  with state transition diagrams
• Special-purpose input technology
• Keypads
• Physical buttons e.g. VCRs
• Touchscreens

7
Key-modal Dedicated-Key Interaction
8
Key-modal Button Interaction
9
Key-modal Menus (inc. Toolbars)
F E V H

• Available actions / objects
• Recognition
• Poor for complex actions or input
• Cumbersome access to info
• Selection techniques
• Pointer
• Typed characters - support response
  chaining
• Voice

10
Key-modal User Activity with Menu

• Form an intention or goal
• REPEAT
• Search for a target
• Consider an option
• Evaluate ref goal
• UNTIL option selected OR
• menu cancelled

11
Key-modal Menu Search and Comparison Operations

• Identity Matching
• Specific target
• Fast matching
• Class-Inclusion Matching
• Top-level panels
• Abstract categories
• User must judge appropriateness
• Equivalence Matching
• Low-level panels
• User has goal but not precise wording
• User thinks up candidate names and synonyms

12
Key-modal Menu Feedback to User

• Selectable options
• If unavailable - fade
• Do not omit options
• Inconsistent screen location
• Does not facilitate browsing
• Visual information
• Option under pointer (highlighted)
• Accelerator keys highlighted (underlined)
• Shortcut keys - displayed
• Options selected so far (tick mark)
• Walking menu (arrow)
• Dialogue box ( ... )
• Separator line
• End of selection process - menu disappears

13
Key-modal Considerations within a Single Menu
Panel

• Overall aim - reduce search time
• Choice of names or icons - main cause of errors
  is unclear meaning e.g. miscellaneous
• Essential to test with users
• Top level panels are most error prone
• More general and abstract
• Lower levels are more specific and concrete
• Easy return to previous screen / menu

14
Key-modal Descriptor Line

• Explanatory / descriptive text or list of options
  at next level of hierarchy
• Significant help in understanding meaning
• Increases search time
• Takes up screen space

15
Key-modal Organisation on a Single Panel

• Number of options
• No right number, but 10 is the maximum BT
  recommend
• Grouping Strategies - reduce search time and
  depth of hierarchy
• Categorical
• Conventional e.g. days of week
• Frequency of use
• Importance
• Sequence of use
• Alphabetical
• Rule of thumb guideline
• Number of groups per panel SQRT (options)
• As hierarchy grows, transparency reduces

16
Menus General Points

• Accelerator keys - not for quit or logoff
• Irreversible options should not come first or
  next to (esp. not below) frequently used options

17
Organisation between Panels

• Navigation problem
• Getting lost
• Using inefficient pathway to goal
• Tradeoff between breadth and depth
• Depth increases navigation problem
• Testing by users essential

18
Menus Non-Standard Styles
19
Hypermedia MemexVanevar Bush (1945)
"As we may think" article in Atlantic Monthly
Identified the information storage and retrieval
problem new knowledge does not reach the people
who could benefit from it

• A device where individuals stores all his/her
  books/records/communications etc
• Items can be retrieved rapidly through indexing,
  keywords, cross references,...
• Can annotate text with margin notes, comments...
• Can construct a trail (a chain of links) through
  the material and save it
• An external memory!
• Based on microfilm records - not implemented

20
Key-modal Hypermedia

• Hypertext / hypergraphics include embedded menus
• Structure - directed graph, organized
  hierarchically
• Web browser - the killer app of the 90s

21
Forms (Inc. Spreadsheets)

• Structured means for gathering information
• Suitable where number of options / data values is
  small
• Should be modal if user must compete
  interaction with it before proceeding
• Allow unconstrained order of field entry
• If data is being transcribed from a paper form,
  on-screen form should have similar layout

22
Forms Main Field Types

• User-typed strings
• Validated
• Indicate required syntax e.g. mm/dd/yy
• Unvalidated
• User choices from a list
• Default values (easy to provide)
• Required and optional values
• Distinguish by appearance and/or location
• Dependent values
• System can enforce interdependencies e.g. If
  person is pregnant, then sex must be female

23
Direct Manipulation(As used in GUIs)
3 Principles

• Continuous representation of object of interest
• Physical action instead of complex syntax
• Rapid incremental and (usually) reversible
  operations
• Impact on object of interest is immediately
  visible

Grammar Noun(s) first, then verb i.e. object -
action
24
Benefits of Direct Manipulation

• Novices can learn basic functions quickly
  (usually by demonstration, not formal instruction
  or reading a manual)
• Experts can work very rapidly
• Knowledgeable intermittent users can retain
  operational concepts
• Error messages are rarely needed
• Users can immediately see if their actions are
  furthering their goals
• Users have reduced anxiety because the system is
  comprehensible and actions are (often) reversible

25
Forms Selective Reveal
26
Forms Selective Reveal
27
Widget Gesture
28
Dynamic Queries

• Apply the principles of direct manipulation to
  the database environment
• visual presentation of the query's components
• visual presentation of results
• rapid, incremental and reversible control of the
  query
• selection by pointing, not typing
• immediate and continuous feedback
• Queries entered intiutively - sliders or buttons
• Continuously update results within 100 ms

29
Next 6 Dynamic Query Slides from Ben
Shneiderman,University of Maryland
30
Dynamic Query Screen
31
(No Transcript)
32
(No Transcript)
33
(No Transcript)
34
(No Transcript)
35
(No Transcript)
36
From Ahlberg Truve, 1996
37
http//www.cs.umd.edu/projects/hcil/chi96/paper/cp
s1txt.htm
38
(No Transcript)
39
http//www.cs.chalmers.se/SSKKII/ivee.html
40
(No Transcript)
41
Lifestreams Yale University
42
(No Transcript)
43
(No Transcript)
44
(No Transcript)
45
(No Transcript)
46
(No Transcript)
47
Choice of Interaction Style

• Starting point range of activities to support
  e.g.
• Walk up and use - key modal
• Data entry - forms and command language
• Editing - direct manipulation
• Constrained by cost / hardware / software tools
• Users abilities (e.g. typing) and knowledge
• There is no single best style
• Most interfaces are hybrids

48
Lecture Review

• Linguistic
• Command-line interaction
• Text-based natural language
• Key-modal
• Question-and-answer
• Function-key interactiion
• Menu-based interaction
• Hypermedia
• Direct manipulation
• Forms
• Graphical direct manipulation