Schneiderman, Chapter 3 Flashcards
Week 4 (26 cards)
Explain Shneiderman’s three high-level design principles
Guidelines, principles and theories
- Guidelines. Low-level focused advice about good practices and cautions against dangers
- Principles. Middle-level strategies or rules to analyze and compare design alternatives
- Theories. High-level widely applicable frameworks to draw on during design and evaluation as well as to support communication and teaching. Theories can also be predictive, such as those for pointing times by individuals or posting rates for community discussions
What are guidelines and how can they help us design user interfaces?
Guidelines record interface designers insights and try to guide the efforts of future designers.
Guideline documents help by developing a shared language and then promoting consistency among multiple designers in terminology usage, appearance, and action sequences
What are principles
Determine users’ skill levels
Identify the tasks
Choose an interaction style
What does it mean to determine user’s skill levels?
All design should begin with an understanding of the intended users.
A generic separation into novice or first-time, knowledgeable intermittent, and expert frequent users
might lead to differing design goals
What does it mean to identify the tasks
Breaking high-level tasks down in smaller (atomic tasks)
Considering the frequency of tasks
- Frequent actions might get dedicated keys/buttons
- Less frequent actions might need a modifier key, a context menu, or a regular menu
- Infrequent actions or complex actions might require menu selections or form fill-ins
What are the different interaction styles?
Direct manipulation
Navigation and menu selection
Forms fill-in
Command language
Natural language
What are the advantages and disadvantages of direct manipulation
Advantages:
- Visually presents task concepts
- Allows easy learning
- Allows easy retention
- Allows errors to be avoided
- Encourages exploration
- Affords high subjective satisfaction
Disadvantages:
- May be hard to program
- Accessibility requires special attention
What are the advantages and disadvantages of navigation and menu selection
Advantages:
- Shortens learning
- Reduces keystrokes
- Structures decision making
- Permits use of dialog-management tools
- Allows easy support of error handling
Disadvantages:
- Presents danger of many menus
- May slow frequent users
- Consumes screen space
- Requires rapid display rate
What are the advantages and disadvantages of forms fill-in
Advantages:
- Simplifies data entry
- Enables convenient assistance
- Permits use of form-management tools
Disadvantages:
- Consumes screen space
What are the advantages and disadvantages of command language
Advantages:
- Powerful
- Allows easy scripting and history keeping
Disadvantages:
- Requires learning and retention
- Error-prone
What are the advantages and disadvantages of natural language
Advantages:
- Relieves burden of learning syntax
Disadvantages:
- Requires clarification dialog
- May not show context
- May require more keystrokes
- Unpredictable
Name the eight golden rules
- Strive for consistency
- Seek universal useability
- Offer informative feedback
- Design dialogs yield closure
- Prevent errors
- Permit easy reversal of actions
- Keep users in control
- Reduce short-term memory load
Explain the different theory types; descriptive, explanatory, prescriptive and predictive
Descriptive: Describes user interfaces and their uses with consistent terminology and taxonomies
Explanatory: Describes sequences of events with causal relationships
Prescriptive: Offers guidelines for designers to make decisions
Predictive: Enables comparison of design alternatives based on numeric predictions of speed of errors
Explain the human capacities; motor, perceptual and cognitive
Motor: Skill in pointing, clicking, dragging, or other movements
Perceptual: Visual, auditory, tactile, and other human sensory inputs
Cognitive: Problem solving with short- and long-term memory
Explain the design-by-levels theory
- The conceptual level is the user’s “mental model” of the interactive system.
- The semantic level describes the meanings conveyed by the user’s input and by the computer’s output display
- The syntatic level defines how the user actions that convey semantics are assembled into complete
sentences to perform certain tasks. - The lexical level deals with device dependencies and with the precise mechanisms by which users
specify the syntax
Explain Norman’s seven stages of action
- Forming the goal
- Forming the intention
- Specifying the action
- Executing the action
- Perceiving the system state
- Interpreting the system state
- Evaluating the outcome
What are Norman’s four principles of good design?
The state and the action alternatives should be visible
There should be a good conceptual model with a consistent system image
The interface should include good mappings that reveal the relationships between stages
Users should receive continuous feedback
What is consistency theory?
Strive for consistency in objects and actions, shown by words, icons, colors, shapes, gestures, menu
choices
The argument for consistency is that if terminology for objects and actions is orderly and describable by a few rules, users will be able to learn and retain them easily
What is contextual and dynamic theory?
Contextual: Support users who are embedded in emotional, physical, and social environments
Dynamic: Design for evolution of user behavior as users move through levels of mastery, performance,
and leadership
What is Micro-HCI?
Design-by-levels, stages-of-action and consistency theory.
They cover measurable performance in terms of speed and errors. It is best studied with laboratory set
experiments and statistical tests
What is Macro-HCI?
Contextual and dynamic theory
Emphasizes the user experience, the usage context, and social engagement. It is best studied with ethnographic observation of users doing work in their familiar context over days or months
What is an error
Any situation in which an action sequence does not lead to the intended result
Can happen for two reasons:
- An error in planning resulting in wrong choice of action
- An error in execution: slipping up in executing the action sequence
What is a slip in terms of errors?
A physical action goes wrong
Example: Hit the wrong button by mistake
What is a lapse in terms of error?
Forget to perform a required or important action
Example: Forgetting to set the resolution of a video before export
