Efficient (Re)presentation

Why Efficient Representations? | How You Can Apply Efficient Representations | Efficient Data Representation for Data to be Manipulated by Users | Efficient Representation of Functionality

This principle states that is is important to choose the right representation.

Why Efficient Representations?

Using efficient representations can make certain tasks dramatically easier. The proper choice of a representation can let users work more efficiently and reduces or even prevents errors (which also makes users more efficient).

How You Can Apply Efficient Representations

Choosing an efficient representation is important for data and functionality. This covers:

Data to be processed by the program
Data to be manipulated by the user, e.g. input values
Functions to be selected and initiated by users.

Efficient Data Representation for Data Being Processed

The purpose of many applications is to present information to the users. The better the chosen representation conveys the central aspects of the data, the better and faster users will understand what the data means. So, ask first what the central aspects of the data are and then choose a representation.

Do not use fancy representations that are "modern" (for example, 3D graphics) but actually obscure or distort the data.

Consult text books on data display if you are in doubt which representation to choose. Consider alternate representations for clarifying different aspects of the data.

Efficient Data Representation for Data to Be Manipulated by Users

If users also have to manipulate the data you may have to choose a different presentation for that purpose. Here, the most important aspect is the ease-of-use of manipulating the data. You may also want to provide different views for judging the results of the manipulations.

Efficient Representation of Functionality

This is an often overlooked but nonetheless very important aspect of application design. Efficient representation of functionality means that users can easily find and access the functions in your application. This in turn means that users perform their tasks efficiently with your application.

This aspect is closely related to the psychological concept of availability, which is also a good "rule of thumb" for user interface designers. This concept states that people are only aware of the things that reside in their working memory or are easily visible in their environment. For example, when thinking about statistical problems, people only consider the cases that they know well and may come up with very biased conclusions. In the context of interface design, availability means that users often only use the functionality and information that they are directly aware of. For example, they use only those functions that are presented in toolbars or as pushbuttons on the screen but do not search the menus for them. Other examples are screen titles and status bars: These are often overlooked because they are not in the users' focus of attention as they are presented in peripheral screen locations.

In graphical user interfaces, applications usually present their functionality in – more or less standardized – menus. In addition, most applications provide toolbars, floating palettes, or pushbuttons on the screen for easier access to frequently-used functions. Usually, functions are accessed through the mouse. In some cases users find using the mouse rather disturbing. Therefore, there are also several methods accessing the functionality with the keyboard.

Here are some tips for making access to functions more efficient:

Important / Frequently used functions: Check which functions are the most important and / or often used ones. Try to give priority access to these functions and make the access as easy as possible. Do not bury frequently used functions in deeply nested menus. Remember that functions that are hard to find may never be known to the users (availability heuristic: you only use what you see).
If you are not sure which functions are most often used / important consider customizable toolbars.
In-place functionality: Place functions close to the screen elements they act on, so that it is obvious which elements they refer to. Provide in-place functionality where possible because this makes functions easily available to users.
Missing menus: Web applications do not have menus. You have to provide all functionality on pushbuttons. The same is true for dialog windows. Therefore, limit the functionality in such cases to the necessary in order not to clutter the screen (or to confuse the user).
Keyboard access: For power users, keyboard access can be very important. Therefore, provide keyboard access at least to the most important and / or frequently used functions.