12. Tone of language

Language choice has a direct effect on how users view the interface.

Use language that the intended user will understand.

For instance the general public should not be expected to understand technical jargon. Consider a warning message such as this

{Error 1001: Stack Overflow at #1002F}

This warning may be very useful for the original software developers but utterly useless as a general message. The same warning message for general use might say

{ Sorry, but the disk is full, please remove files to continue}

The message explains the problem in plain English and also lets the user know what they can do about it.

Keep the intended user in mind when setting out the language. Avoid over-complicated and condescending tone.

Always let the user know what they can do next

For example consider a form being filled in by the user and they have not entered a valid date.

1. A poor design of the error message
The resulting message is "Invalid date entered"
This does not help the user as they are still unaware of the acceptable format

2. A better design of error message
The resulting message is "Invalid date entered, use dd/mm/yyyy format

Now they know what to do.