What do you mean by directing manipulation and indirect manipulation

Q.What do you mean by directing manipulation and indirect manipulation? (5 M) (DEC 16 /MAY 16 /DEC 17)

Ans:-

Direct manipulation:-

• Definition:- Direct manipulation (DM) is an interaction style in which users act on displayed objects of interest using physical, incremental, reversible actions whose effects are immediately visible on the screen.
•  Example:
• dragging a document to the trash
• changing the size of a triangle by interacting with a visual representation of a triangle
• inserting characters in a document by pointing to where they should go (with a mouse/cursor/insertion point) and then typing
• “dialing” a phone number by pushing numbers on a keypad
• playing a song using controls like a physical tape deck or CD/DVD player

Moving a file on MacOS using direct manipulation involves dragging that file from the source folder and moving it into the destination folder.

• Characteristics:
• The task objects are manipulated by physical actions, such as clicking or dragging, rather than by entering complex syntax.
• There is a visible and continuous representation of the task objects and their actions. Consequently, there is little syntax to remember.
• Rapid learning
• Their effects on task objects are immediately visible.
• Reversibility of (almost) all actions 
• Users can explore without severe consequences 
• Syntactic correctness 
• every operation is legal
• Disadvantages:
• DM is slow
• Repetitive tasks are not well supported.
• Some gestures can be more error-prone than typing
• Accessibility may suffer

Indirect manipulation:-

• Indirect manipulation substitutes words and text, such as pull-down or pop-up menus, for symbols, and substitutes typing for pointing.
• Most windows system are a combination of both direct and indirect manipulation 
• Example:
• A menu ma be accessed by pointing at a menu icon and then selecting it( direct manipulation)
• The menu itself, however, is a textual list of operations (Indirect manipulation)
• When an operation is selected from the list, by pointing or typing the system executes it as a command

• Disadvantages:
• The operation may be difficult to conceptualize
• Graphics capability limited
• Amount of space available for placing manipulation controls in the window border may be limited.
• Difficult to remember all the necessary operations