Pattern from Ger Koelman

 Example Usability Design Pattern:

On the next pages a sample Usability Pattern is provided that can very well be related to Alexanders design pattern number 57: Children in the city.

The description is given in the structure we have chosen for specifying the Patterns we have found during our study.  Other Patterns were e.g. Virtual screens, Navigation Centre, Visible actions, User Guidance, Feedback, Chunking, Input Form, Retrievable History.

4 Explorable Interface



The easiest way for people to get familiar with a new environment is by exploring it and experimenting with it.


Design the system such that inexperienced users can explore the system without any great risks.


Novice users could be offered system guidance, showing them the right procedures in completing a specific task. This however shows them only one way the get things done. The chance that they will find other useful functions, that are less obvious from their level of experience, is also very small.

In an explorable system, the user can develop own procedures by trial and error. Once he found a proper way to get the job done, he has developed a procedure that best fits his mental model of the system. Exploring the system will gradually reveal the system functions to the user.


(Here, reference should be made to alternative patterns)


The Windows 95 operating system, as well as many of the Microsoft Office applications, are good examples of explorable interfaces. They all provide the option to Undo the last modification(s) made.
This allows the user to tryout an option to observe the result. If he doesn’t like it, he can make his changes undone.



Complex systems with many functions.


If novice users cannot explore the entire system, they will never become expert users. Many modern systems are so complex that novice users cannot explore them without the risk of making dangerous mistakes.


“One important method of making systems easier to learn and to use is to make them explorable, to encourage the user to experiment and learn the possibilities through active exploration. This is how many people learn about (...) a new stereo system (...). Work the buttons while listening and looking to see what happens. The same can be true with computer systems.”(Donald Norman).

Also consider the fact that nobody likes reading the manuals.



Systems, being used by both novice and expert users.


Design the system in such a way that the main flow of any dialogue gives access to only the basic tasks performed by the user. These user actions should be made reversible where possible.
Destructive and other dangerous actions, should be confirmed by the user.
Expert functions are to be selected explicitly. The system should however provide shortcuts to these functions for the expert user.

Related Patterns

7 User Guidance
8 Visible Functions


An example pattern prepared for the Usability Pattern Language Workshop at Interact '99