Feedback
Why Feedback? | How You Can Provide Feedback | Visual Feedback | Acoustic Feedback
Feedback provides users with clues about the effectiveness of their actions and what is going on in an application.
See also Understanding, Learning and Relearning for more information and examples on this topic.
Why Feedback?
Feedback can relate to user actions but also to system actions or the system status.
Feedback helps users to maintain orientation in an application. Users usually gather information on the current status, perform an action, and then check the results with respect to their goals. Therefore, immediate feedback on user actions is very important to make such judgments possible.
Feedback is also very effective for learning and for establishing trust in an application. By experiencing which actions are successful and which are not, users can build up the right strategies for interacting with an application.
How You Can Provide Feedback
Feedback can be given in a number of ways, for example, by:
- Sending messages in status areas or dialog boxes. These messages may tell the system status, the success or failure of user actions, or may prompt the user for additional input or actions
- Providing visual feedback, for example, by highlighting active interface elements
- Providing acoustic feedback, for example, if an action is not possible
There are discussions about the pros and cons of visual and acoustic feedback. Our opinion is that both have their uses, although acoustic feedback always needs visual support – at least if it is turned off. You cannot rely on acoustic feedback alone because there are situations where it cannot be used.
Visual Feedback
- Pro: Can be very flexible with respect to representation (text, graphics, animation, etc.), style, length, etc.
- Pro: Spatial = parallel presentation that can be easily scanned
- Pro: Does not usually go away
but stays on screen so that it will catch the users' attention.
Example: Error or status messages in reserved areas
Bad Example: Messages in status areas that disappear after a mouse move or click - Pro: Can be "in place,"
that is, closely related to the interface element, which it refers to
Example: Feedback for links or button presses - Pro: Does not disturb colleagues
or other people in the same room
- Con: Often competes for screen
space with the information which it refers to
Example: Error messages are often difficult to place on the screen, at least close to the object which they refer to - Con: Require users to look at
the screen
Example: Users want to work on other things while a longer lasting process is going on. They have to repeatedly look at the screen, in order to see the current status of the process
As a general rule, visual feedback is well suited to situations where more complex information has to be presented to the user and where acoustic feedback is not adequate because it may disturb other people or the environment is noisy.
Acoustic Feedback
- Pro: Does not compete with information
on the screen
Example: Error beeps during a mouse drag do not clutter the screen - Pro: Is on a different sensory
channel than screen information; therefore, humans can process it in
parallel to visual information
Example: Error beeps during a mouse drag do not require the user to shift attention and to look at error messages somewhere on the screen - Con: Limited sound vocabulary
(except if longer texts are read); assignment of sounds to actions or
elements is often arbitrary
Example: A beep or a "blurb" may have many interpretations - Con: Is a sequential presentation that has to be listened to more or less for the whole message
- Con: Is transient, that is, the message or sound is gone after it has been issued; users may not have listened to it (in some cases it may be possible to repeat the sound)
- Con: There is no spatial relationship to the interface element that it refers to. A relationship can only be established by closeness in time or meaning. For example, if the sound appears directly during a mouse or keyboard action a connection can be established. Otherwise, however, the referred element has to be named
- Con: May disturb colleagues or other people that are in the same room (or requires the use of headsets)
- Con: Not usable in noisy environments (or requires the use of headsets)
As a general rule, acoustic feedback is well suited to direct physical actions.
Source: Simplifying for Usability