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Display, Control - Coggle Diagram

- - - - A display should look like the variable that it represents.
        etc: Temperature (High and low value, a thermometer should orieted vertically)
    - - The moving element(s) of any display of dynamic information should move in a spatial pattern
        etc: Aircraft
  - - - Sometimes two or more sources of information are related to the same task and must be mentally integrated to complete the task
    - - Sometimes processing a lot of information can be facilitated by dividing that information across resources
      - Presenting visual and auditory information concurrently rather than presenting all information visually or auditory.
    - - Good designs are those that minimize the net cost by keeping frequently accessed sources in a location in which the cost of traveling between them is small.
      - However, such guideline should be employed carefully because very small size can degrade legibility
  - - - Sometimes expectancies based on long term memory.
      - People perceive and interpret signals in accordance with what they expect to perceive on the basis of their past experience.
    - - When the viewing/listening conditions are degraded, a message is more likely to be interpreted correctly when the same message is expressed more than once
      - Same message is presented in alternative physical forms.
        etc: Voice + print, color + shape, LED + Warning tone
    - - Do not require the user to judge the level or a represented variable on the basis of a single sensory variable (color, size of loudness)
      - Etc: When traffic light turns yellow? Fuel warning - how much more left
    - - When confusion could be serious, the designer should delete unnecessary similar features and highlight dissimilar (different) ones in order to create distinctiveness.
      - Similar signals are likely to be confused either at the time they are perceived or after some delay if the signals must be retained in STM before action is taken.
    - - Critical to the design of good displays
      - Necessary for creating usable displays
      - Once displays are legible, additional perceptual principles should be applied.
      - Relating to issues such as: contrast, visual angle, illumination, noise, masking
  - - - People ought not be required to retain important information solely in STM or retrieve it from LTM.
        etc: Phonebook, checklist, traffic sign
      - Sometimes too much knowledge in the world can lead to clutter problems and systems designed to rely on knowledge in the head are not necessary bad.
    - - Humans are not very good at predicting the future.
        
        prediction is a difficult cognitive task depending heavily on STM
    - - Old habits die hard.
      - Design displays in a manner that is consistent with other display that the user may be perceiving concurrently or may have perceived in the recent past.
        
        Example : red means the same thing at any display designs
- - - - Physical feel
        
        Should be some feedback as to state change.
        
        Feedback is a critical, positive feature of discrete controls.
        
        Touch screen, push button do not do so well in giving obvious feedback.
        
        Care should be taken in the design of discrete controls.
      - Size ; use larger size, spacing between controls
        Confusion & labeling ; should be well specified and meaningful
      - When control-display relationships are compatible:
        
        Learning is faster
        
        Reaction time is faster
        
        Few errors are made
        
        User satisfaction is higher
      - Positioning Control Devices
        
        A common task in much of human machine interaction is the need to position some entity in space
        
        Spacial tasks involving positioning or pointing
        Etc:
        
        Moving a cursor to a point on a screen, reaching with a robot arm to contact an object, or moving the setting on a radio dial to a new frequency.
        
        Mouse, joystick, thumbpad, are available to accomplish such tasks
        
        Movement time
        
        Control require two different movements
        etc: movement for the hands/fingers to reach the control device
        movement of the control device in some direction to position a cursor
        
        Fitt's Law
        
        The amout of time required to move a pointer (eg. mouse cursor) to a target area is a function of the distance to the target divided by the size of the target.
        
        category of control devices to accomplish pointing or position tasks
        
        Indirect position controls
        
        Changes in the position of the limb directly correspond to changes in the position of the cursor
        etc: mouse, touchpad, tablet
        
        Indirect velocity controls
        
        An activation of control in a given direction yields a velocity of cursor movement in that direction
        
        Joystick, cursor keys
        
        Direct position controls
        
        The position of the human hand directly corresponds with the desired location of the cursor
        etc: Light pen, touch screen
        
        Voice controls
  - - - Example scenario
        (Control Panel Layout)
        
        Controls and displays should be arranged in functional and/or sequential groups
        
        Components should be grouped based on function
        
        The number of controls should be kept to a minimum
        
        Control panels should minimize eye movement and hand travel, but maintain adequate space for visual discrimination and control activation.