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 Metaphores
> 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

e) 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

e) 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

e) 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

e) 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

e) 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

e) 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

e) 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

e) 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

e) 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

e) 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