What does the term 'test design technique' refer to in testing?

The term 'test design technique' refers to a method for deriving test cases. This involves systematic approaches or strategies used to create and structure test cases that will effectively evaluate the functionality of the software under test. By employing various test design techniques, testers can ensure comprehensive coverage of requirements, including functional and non-functional aspects of the application. These techniques can include methods like equivalence partitioning, boundary value analysis, cause-effect graphing, and state transition testing, among others. Each technique serves a specific purpose and helps in identifying test scenarios that might otherwise be overlooked, thus enhancing the quality of testing outcomes.

The other options focus on different aspects of the testing process and do not encapsulate the essence of what a test design technique is. For example, a set of test execution outcomes pertains to the results obtained after tests have been executed, while a collection of test environment tools relates to the software and hardware setup needed to execute tests. Pre-conditions required for testing describe necessary states or conditions that must be met before testing can take place. None of these directly refer to the derivation of test cases, which is the central aspect of test design techniques.