**Visibility of system status**

The system should always keep users informed about what is going on, through appropriate
feedback within reasonable time

**Match between system and the real world**

The system should speak the users' language, with words, phrases and concepts familiar to
the user, rather than system-oriented terms. Follow real-world conventions, making information appear
in a natural and logical order.

**User control and freedom**

Users often choose system functions by mistake and will need a clearly marked "emergency exit" to
leave the unwanted state without having to go through an extended dialogue.  Support undo and redo.

**Consistency and standards**

Users should not have to wonder whether different words, situations, or actions mean the same thing.
Follow platform conventions.

**Error prevention**

Even better that good error messages is a carefule design which prevents a problem from occurring in the
first place.  Either eliminate error-prone conditions or check for them and present users with a confirmation
option before they commit to the action.

**Recognition rather than recall**

Minimize the users's memory load by making objects, actions, and options visible. The user should not
have to rememebr information from the one part of the dialogue to another. Instructions for use of the system
should be visible or easily retrievable whenever appropriate.

_**Flexibility and efficiency of use**_

_Accelerators -- unseen by the novice user -- may often speed up the interaction for the expert user such that
the system can cater to both inexperienced and experienced users.  Allow users to tailer frequent actions._

**Aesthetic and minimalist design**

Dialogues should not contain information which is irreleveant or rarely needed.  Every extra unit of
information in a dialogue competes with the relevant units of information and dimishes their relative visibility.