4.4.1 Error Guessing

Error guessing is a technique used to anticipate the occurrence of errors, defects, and failures, based on the tester’s knowledge, including:

• How the application has worked in the past

• What kind of errors tend to be made

• Failures that have occurred in other applications

A methodical approach to the error guessing technique is to create a list of possible errors, defects, and failures, and design tests that will expose those failures and the defects that caused them. These error, defect, failure lists can be built based on experience, defect and failure data, or from common knowledge about why software fails.