Direct Manipulation

The term direct manipulation is given by Shneiderman (1982) as they possess the following characteristics:

i. The system is portrayed as an extension of the real world.

ii. Continuous visibility of objects and actions.

iii. Actions are rapid and incremental with visible display of results.

iv. Incremental actions are easily reversible.

Example for direct manipulation:

Driving an automobile

The scene is directly visible through the front window and performance of actions such as braking or steering has become common knowledge in our culture. To turn left, the driver simply rotates the steering wheel to the left. The response is immediate and the scene changes, providing feedback to refine the turn.

In the above example, a driver looking at an object directly manipulates the scenario by his sudden action, which can be referred as direct manipulation.

Indirect Manipulation

In practice, direct manipulation of all screen objects and actions may not be feasible because of the following:

i. The operation may be difficult to conceptualize in graphical system.

ii. The graphics capability of the system may be limited.

iii. The amount of space available for placing manipulation controls in the window border may be limited.

iv. It may be difficult for people to learn and remember all the necessary operations and actions.

When this occurs, indirect manipulation is provided. Indirect manipulation substitutes words and text, such as pull-down or pop-up menus, for symbols and substitutes typing for pointing.

Most window systems are a combination of both direct manipulation and indirect manipulation. A menu may be accessed by pointing at a menu icon and then selecting it (direct manipulation) or the menu itself is a textual list of operations (indirect manipulation).