Dialog Styles

1
Dialog Styles
2
The Five Primary Styles of Interaction

• Menu selection
• Form fill-in
• Command language
• Natural language
• Direct manipulation

3
Menu Selection

• Employs metaphor of restaurant menu
• Users read list of items select appropriately
  according to task apply syntax to indicate
  selection confirm choice initiate action
  observe effect
• Designers may need to use careful task analysis
  to ensure all functions supported conveniently,
  and that terminology is appropriate and
  consistent in use

4
Advantages and Disadvantages of Menu Selection

• Advantages
• shortens learning curve
• reduces keystrokes
• structures decision-making
• permits use of dialogue-management tools
• allows easy support of error-handling
• Disadvantages
• imposes danger of deep-nested menu hierarchies
• may slow frequent users
• consumes screen real estate
• requires rapid display rate

5
Form Fill-in

• Paper forms can be used as metaphor (or indeed,
  template)
• Users see a display of related fields move a
  cursor among the fields, and enter data as
  appropriate
• Designers need to ensure that users understand
  field labels, appropriate values and the
  data-entry method, and are capable of responding
  to error messages - some user training may be
  necessary

6
Advantages and Disadvantages of Form Fill-in

• Advantages
• simplifies data entry
• requires modest training
• makes assistance convenient
• permits use of form-management tools
• Disadvantages
• consumes screen real estate

7
Command Language

• Appropriate metaphor may be military parade
  ground!
• Users learn syntax can express complex
  possibilities rapidly without reading distracting
  prompts
• Designers must allow for high error-rates
  diversity of possibilities and complexity of
  mapping from task to computer syntax is hard
  user training is necessary

8
Advantages and Disadvantages of Command Language

• Advantages
• flexible
• appeals to power users
• supports user-initiative
• convenient for creating user-defined macros
• Disadvantages
• poor error handling
• requires substantial training and memorisation

9
Natural Language

• Utilises conversational metaphor
• Users enter natural language sentences computer
  often seeks clarification before beginning task
• Designers need to understand task domain to
  narrow range of interpretations to manageable
  level design is extremely difficult.

10
Advantages and Disadvantages of Natural Language

• Advantages
• relieves burden of learning syntax
• no training!
• Disadvantages
• requires clarification dialogue
• may require more keystrokes
• may not show context
• is unpredictable

11
Direct Manipulation

• Metaphor is of a virtual world representing the
  real world
• Users point at visual representations of objects
  and actions, carry out tasks rapidly and see
  immediate results keyboard control replaced by
  cursor-motion control devices
• Designers need to choose appropriate icons and
  graphics to successfully immerse the user -
  minimal user training indicated

12
Advantages and Disadvantages of Direct
Manipulation

• Advantages
• presents task concepts visually
• easy to learn
• easy to retain
• permits error avoidance
• encourages exploration
• permits high subjective satisfaction
• Disadvantages
• may be hard to code
• may require graphics displays and pointing devices

13
Shneidermans Eight Golden Rules of Dialogue
Design

• 1. Strive for consistency
• 2. Enable frequent users to use shortcuts
• 3. Offer informative feedback
• 4. Design dialogues to yield closure
• 5. Offer simple error handling
• 6. Permit easy reversal of actions
• 7. Support internal locus of control
• 8. Reduce short-term memory load