3RD QUIZ

• Interaction involves at least two participants: the user and the system
• domain  – the area of work under study

  e.g. graphic design (geometric shapes, a drawing surface, and a drawing utensil)
• task  – how you go about doing it  – ultimately in terms of operations or actions

  e.g. … select the fill tool, click over the triangle
• goal  – what you want to achieve

  e.g. create a solid red triangle
• Intention – is a specific action required

   to meet the goal
• Donald Norman’s model

  • user establishes the goal
  • formulates intention
  • specifies actions at interface
  • executes action
  • perceives system state
  • interprets system state
  • evaluates system state with respect to goal

  •Norman’s model concentrates on user’s view of the interface

  
• Gulf of Execution

    user’s formulation of actions 

  ≠  actions allowed by the system

  (The gulf of execution is the difference between the user’s formulation of the actions to reach the goal and the actions allowed by the system.)
• Gulf of Evaluation

    user’s expectation of changed system state 

  ≠  actual presentation of this state

  (The gulf of evaluation is the distance between the physical presentation of the system state and the expectation of the user.
• slip

  •  understand system and goal 
  • correct formulation of action 
  • incorrect action
• mistake

   may not even have right goal!
• Abowd and Beale framework

  
  

  extension of Norman…

  their interaction framework has 4 parts

  • user
  • input
  • system
  • output
• Using Abowd & Beale’s model

  
• Ergonomics

  Study of the physical characteristics of interaction

  Also known as human factors – but this can also be used to mean much of HCI!
• Industrial interfaces

  
• glass interface

  - cheaper, more flexible,multiple representations, precise valuesloss of context,

  –not physically located, complex interfaces
• office – direct manipulation–user interactswith artificial world
• •industrial – indirect manipulation–user interactswith real worldthrough interface
• Command line interface - Way of expressing instructions to the computer directly

  function keys, single characters, short abbreviations, whole words, or a combination
• Menus - Set of options displayed on the screen
• Natural language

  • Familiar to user
  • speech recognition or typed natural language
• Query interfaces

  • Question/answer interfaces –userled through interaction via series of questions – suitable for novice users but restricted functionality – often used in information systems
• Query languages – used to retrieve information from database
• Form-fills

  • Primarily for data entry or data retrieval
  • Screen like paper form.
• Spreadsheets - sophisticated variation of form-filling.

  • grid of cells contain a value or a formula
  • formula can involve values of other cells  e.g. sum of all cells in this column
• WIMP Interface

  • Windows
  • Icons
  • Menus
  • Pointers
• WIMP Interface - default style for majority of interactive computer systems, especially PCs and desktop machines
• Point and click interfaces - just click something!

  –icons, text links or location on map
• Three dimensional interfaces

  • virtual reality
  • ‘ordinary’ window systems
  • 3D workspaces
• Windows - Areas of the screen that behave as if they were independent

  • can contain text or graphics
  • can be moved or resized
  • can overlap and obscure each other, or can be laid out next to one another (tiled)
• scrollbars – allow the user to move the contents of the window up and down or from side to side
• title bars – describe the name of the window
• Icons

  • •small picture or image
  • •represents some object in the interface
• Pointers

  • important component –WIMP style relies on pointing and selecting things
  • •uses mouse, trackpad, joystick, trackball, cursor keys or keyboard shortcuts
  • •wide variety of graphical images
• Menus

  • •Choice of operations or services offered on the screen
  • •Required option selected with pointer
• Menu Bar at top of screen (normally), menu drags down

  • pull-down menu - mouse hold and drag down menu
  • drop-down menu - mouse click reveals menu
  • fall-down menus - mouse just moves over bar!
• Contextual menu appears where you are

  • pop-up menus - actions for selected object
  • pie menus - arranged in a circle
• Cascading menus – hierarchical menu structure
• Keyboard accelerators - key combinations - same effect as menu item

  two kinds

  • active when menu open – usually first letter
  • active when menu closed – usually Ctrl + letter
• Buttons - individual and isolated regions within a display that can be selected to invoke an action 
• radio buttons –  set of mutually