Chapter 17 -- Direct Manipulation is Cool

Chapter 17

A user is performing a task using direct manipulation when the following occurs:

  • There is an object visible on the screen.
  • The user can interact directly with the object, typically by using the mouse.
  • There is immediate feedback that shows the current results of the interaction.

All three of these requirements are essential to direct manipulation. If any one of them is missing, the sensation of directness is destroyed. By this definition, the MS-DOS command line is the antithesis of direct manipulation. There are no visible objects on the screen except the command prompt, you have to type in each command (and the interface doesn't help you if you don't know what to type), and you receive little or no feedback so you don't know for sure whether a command you typed in worked.

In practice, direct manipulation often boils down to an even simpler definition: the ability to interact with a screen object directly by using the mouse instead of indirectly by using the keyboard, dialog box, or menu bar. It is the use of a mouse to interact with a screen object that creates the essential sensation of directness. You feel as if you are manually manipulating the object, and it's possible at times to lose your awareness that software is involved. The mouse feels like an extension of your hand. The object and what you are doing to the object seem more "real" than other kinds of interaction with a program, such as that in the MS-DOS command line example I just mentioned.

Direct manipulation has numerous advantages. It is a natural way to perform tasks in a modern graphical user interface, is easy to learn, and is quick and convenient to use. If the extent of manipulation is properly restrained, you can avoid the need for error messages. Direct manipulation is also easy to remember—once you learn how to manipulate an object directly it's unlikely that you'll forget how. Best of all, direct manipulation makes you feel as if you're directly in control of the task at hand and its continuous visual feedback makes it easy for you to decide when you have what you want. Simply put, direct manipulation makes using software fun.

TIP
Direct manipulation makes using software fun. It is the ultimate form of interactivity.

In the remainder of this chapter, I'll present the alternatives to direct manipulation, the various types of direct manipulation commonly found in Microsoft Windows programs, the problems with direct manipulation, and how to solve these problems.



Developing User Interfaces for Microsoft Windows
Developing User Interfaces for Microsoft Windows
ISBN: 0735605866
EAN: 2147483647
Year: 2005
Pages: 334

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