14
2.
Serve Universal Usability
As the frequency of use increases, so do user’s desires to reduce the
number of interactions and to increase the ease of interacting to the
system. Abbreviation’s function keys, hidden commands, and macro
facilities are very helpful to an expert user.
3.
Offer Informative Feedback
For every user inputs to the system, there should be some system
feedback. For frequent and minor actions, the response can be
modest, while for infrequent and major actions, the response should
be more substantial.
4.
Design Dialog to Yield Closure
Sequences of actions should be organized into groups with a
beginning, middle, and end. The informative feedback at the
completion of a group of actions gives the operators the satisfaction
of accomplishment, a sense of relief, the signal to drop contingency
plans and options from groups’
minds, and
an indication that the
way is clear to prepare for the next group of actions.
5.
Offer Simple Error Handling
Design the system so that the user cannot make a serious error. If an
error is occurred, the system should be able to detect the error and
offer simple and comprehensible mechanism for handling the error.
6.
Permit Easy Reversal of Actions
Design the system so that whenever the users mistakenly input
something into the system, it may be reversible to the previous state
before inputting.
7.
Support Internal Locus of Control
Design the system to make users the initiators of actions rather than
the responders. Due to the desire of experienced operators that they
are in charge of the system and that the system responds to users’
actions.
8.
Reduce Short-Term Memory Load
The limitation of human information processing in short-term
memory requires that displays be kept simple, multiple page
 |