a) Conceptual Design

• Design and communicate a good conceptual model

• A well-designed interface is transparent

• Design an interface that visually communicates its conceptual model

• Use progressive disclosure – structure the interface semantically

• Provide meaningful paths and exits

• Well-designed conceptual model helps

  • Learnability to advanced beginners and competent performers

  • Ease of use, error-free use, retention over time and subjective satisfaction for competent

  • and expert performers

b) Use Metaphors

• Metaphors help users to build a conceptual model

• Design icons and visual relative to each other to enhance the metaphor

• Not all widgets are metaphors

• Don’t need to take metaphors to logical extremes if it does not suit the design

• Metaphors helps in

  • Learnability, ease of use and subjective satisfaction for novices and advanced beginners

  • Retention over time for all users

c) Use Constrains

• The software encourages the user to do the right things at the right time

• Prevents or discourages from doing wrong things and warns about the consequences

• Constraints

• Are good for novices and advanced beginners to minimize errors, help them learn the interface

  • make it easier and faster to use

  • May hamper competent and expert performers

d) Affordances and Mappings

• It should be possible to determine the relationships

  • Between actions and results

  • Between controls and their effects

  • Between the system state and what is visible

• Make controls look and feel different

• Affordances and mappings

  • Help novices and advanced beginners learn the interface, make it easier and faster to use

  • and help in minimizing errors

  • Help competent performers to retain the interface over time

  • Help in mission-critical applications

e) Direct Manipulation

• Allow users to directly manipulate objects

• Use the object-action paradigm wherever possible

• Extend metaphors only as long as it does not directly contradict the mental model

  • Helps novices and advanced beginners to learnability, ease of use and subjective satisfaction

f) Visual Design

• Use visuals for effective communication

• Design all visual elements relative to each other to enhance the conceptual model

• Promote visual clarity – avoid clutter

• Use visual work together with text

• Graphics – icons, windows, dialog boxes, buttons – need to be designed as a communicative environment

• Clear and consistent visual design

  • Improves learnability for novices and advanced beginners

  • Aids recall and subjective satisfaction for novices, advanced beginners and competent performers

g) Consistency

• Effective applications are consistent within themselves as well as with one another

• WYSIWYG(what you see is what you get)

• Sustain the context of user tasks and data. Be consistent with

  • Data across views

  • Results of actions

  • Functionality across tasks

  • Sequence of tasks

• Be consistent between applications

• Allow interoperability with other applications

• Be consistent across versions

• Be consistent in visual design

• Consistency

  • Improves error free use for all users

  • Helps advanced beginners learn from other applications

h) Feedback

• People expect physical actions to give physical results

• Feedback makes users a feel that they are in charge

• Give users full and continuous feedback about the results of actions

• Be brief and direct, use user’s vocabulary

• Establish proper ‘tone of voice’

• User time is precious – make good use of it

• Give feedback to help users to detect and correct errors

• Use sound for feedback selectively

• Be useful rather than cute

• Sounds are intrusive – benefit as well as a drawback

• Good feedback

  • Helps novices, advanced beginners and competent performers learn quickly

  • Allows error recovery and improves ease of use and subjective satisfaction for all users

i) Visibility

• By looking, the user can tell the state of the device and the alternatives for action

• Dim out actions not available currently, but don’t make them invisible

• Provide visual clues to allow users to understand where they are, what they are doing and what they can do next

  • Helps novices, advanced beginners and competent performers to learn the interface, makes it easy and error free to use and enhances subjective satisfaction

  • Improves the retention over time for all users

j) Standards

• If all else fails, standardize

• Following GUI standards helps in

  • Learnability of the interface for novices and advanced beginners

  • Reducing errors in operation for novices, advanced beginners and competent performers

k) Forgiving

• If error is possible, someone will make it

• Design to minimize the occurrence of errors

• Make errors cost free

• Make actions reversible

• Warn about irreversible actions before doing them

• If you allow users to customize, provide a way to restore defaults

• Forgiving interface

  • Makes it more learnable and easy to use for novices and advanced beginners

  • Allows error recovery and enhances experience and subjective satisfaction of all users

l) Minimize User Memory and Task Load

• Minimize use of user short term memory

• Put knowledge in the world

• Users are better at recognition than recall

• Provide visual clues

• Use the power of constraints and forcing functions

• Allow for more efficient operation when the user has learnt the operations, (knowledge in the head)

• Let the computer do what the computer can

  • Ensures learnability and ease of use for novices and advanced beginners

  • Minimizes errors and improves speed

m) Modality

• Use modes judiciously – avoid unnecessary modes

• If using modes, give constant feedback about current mode

• People are often disturbed while they are working, or they often change their mind

• Modes may even be necessary

• Modes can be used for helping novices and advanced beginners

• Careful use of modes can make an interface learnable, error-free use, easy to use and fast to use for novices and advanced beginners

  • A modeless interface will allow competent performers and experts the ease of use as well as speed of use

n) Multiple Input Paths

• Allow users to specify inputs through multiple paths

• Users have different habits at different times

• Users in different stages prefer different methods of input

• Users familiar with a different software will find it quicker to learn your product

• Multiple input paths affects

• Learnability for novices and advanced beginners

  • Ease of use and speed of use for competent and expert users

o) Customization

• Modify look and feel

  • Colors, mouse buttons, tool bars, layouts etc.???

• Enhance functionality

  • Develop custom style sheets, color pallets, add words to dictionary, add names to address books etc

• Empower the experienced user to improve productivity through customization

  • Help users customize user tasks (rather than computer tasks)

• Provide multiple inputs paths

  • Allow for keyboard shortcuts and type-ahead systems

• Customization

  • Helps competent performers and experts to improve speed and ease of use and minimize errors

  • Threatens novices and advanced beginners with complexity of mental models