What is an example of an error?
An error may be defined as the difference between the measured and actual values. For example, if the two operators use the same device or instrument for measurement. It is not necessary that both operators get similar results. The difference between the measurements is referred to as an ERROR.
What is the best error message?
A good error message has three parts: problem identification, cause details if helpful, and a solution if possible. Whenever an error occurs, user wants to fix it as soon as possible. The error message should have enough information for user that guides him how to get out of the erroneous situation.