Who Is in Control?
No Deception! | Brute Force: No! | Brute Force: Yes! | Transparency
To make a system appear simple, it is important to choose the right mixture between system guidance and user control. While beginners and casual users often fare better with appropriate guidance from the system, more experienced users prefer to be in control. Often it is not an easy to find the right mixture, and designers also need to be aware of some of the traps they might fall into.
Motto: Me at the steering wheel!
No Deception!
Logical dependencies between data or task steps often exist, which require that users do the steps, or at least some of them, one after the other. The user interface should not pretend that these steps can be done in an arbitrary order, if this is not the case!
Example: A toolbar or a collection of buttons implies that these buttons can be pressed in any order. If this is not the case, this control or control array is the wrong choice! Online instructions are needed that inform users about the required sequence of button presses.
Example: In an existing application two steps had to be done one after another. In either case a dialogue window was presented whenever the respective button for the step had been pressed. However, if the user pressed the wrong button, the "correct" dialogue that belonged to the other button was presented. This is not the preferred way to teach users how to use an application!
Example: Do not use tabstrips if there are dependencies between views! Users expect that they can click the tabs in any order.
Hint: If there are dependencies, use a wizard that guides the users through a fixed, or at least system-determined, sequence of steps.
Hint: Minimize the use of - or better, do not use - data that controls the flow of the processing (this is a frequently used R/3 "feature"). Users often do not understand dependencies. Dependencies are not intuitive and make an application difficult to learn!
Brute Force: No!
Opposite to the problem mentioned above, do not enforce a sequence of steps, if users can do these in any order!
Example: Use a tabstrip instead of a sequence of screens, if views are independent from each other.
Brute Force: Yes!
As a general rule, guide the users, even if they are professional, if processes are complex and intransparent.
Example: Use wizards or screen sequences to enforce a certain processing order. Wizards make the process more transparent to the users, if they indicate the current position in the process, provide an overview of the process as a whole, and present a preview of the consequences of possible actions.
Transparency
Users often feel uncomfortable and dominated by the system, if it assumes control. Therefore, if system guidance is appropriate, inform the users what is happening and where they are going.
Example: Wizards are a good way to guide users and to keep them informed.
Source: Simplifying for Usability