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Relevant considerations:

In a meaningful interface each label and control needs to be given a considerable amount of thought. The layout and combination need to have a clear purpose and meaning to the user. He needs to intuitively know or recognize how it is to be operated and its function. Label each control so it is clear to the user what it controls and what its intention is.

Use meaningful codes, as they are easier for the user to both recognize and recall, likewise for mnemonic codes and accelerator keys. Single letter mnemonic codes will be easier to remember if one uses the initial letter in the option name.

Use familiar units so the user recognizes the information without having to estimate its value in a known unit. If translations are needed to another unit, the computer can easily do this.

Use conventional colors to display data, but never use color alone. If there is a color convention that is generally recognized in the users environment, apply it. Here is a list of recommended color conventions:

Red: Present data associated with alarms, error conditions, and danger in red. Red also has a strong association with hot temperatures and is therefore well suited to display this kind of data.
Yellow: Present warnings and non critical data in yellow.
Green: Present normal conditions in green. Green also has a strong relation to ``go''.
Blue: Use blue to present cold temperatures. Blue can also be used as background, graphics and data that are not critical; it should not be used for primary data.

Michael Spring
Mon Nov 27 18:39:52 EST 1995