Advantages Disadvantages
Direct manipulation
Visually presents task concepts
Allows easy learning
May be hard to program
May require graphics display and
pointing devices
Allows easy retention
Allows errors to be avoided
Encourages exploration
Affords high subjective satisfaction
Menu selection
Shortens learning
Reduces keystrokes
Structures decision making
Permits use of dialog-management tools
Allows easy support of error handling
Presents danger of many menus
May slow frequent users
Consumes screen space
Requires rapid display rate
Form fillin
Simplifies data entry
Requires modest training
Gives convenient assistance
Permits use of form-management tools
Consumes screen space
Has poor error handling
Requires substantial training and
memorization
Command language
Is flexible
Appeals to "'power" users
Suppo.rts user initiative
Allows convenient creation of user-defined
macros II
Naturallanguage I Relieves burden of learning syntax Requires clarification dialog
!! May not show context
I May require mOre