Final answer:
The technique being applied when deriving test conditions from user stories and acceptance criteria is Black-box testing. This method is used to refine the software's design by testing it against external requirements and evaluating its functionality and weaknesses.
Step-by-step explanation:
When studying a user story and its acceptance criteria to derive test conditions and associated test cases, the test technique being applied is Black-box testing. This approach focuses on testing the software using the external perspective of the software to derive test cases based on specifications, without any knowledge of the internal workings of the application. Early QA and test involvement like this allows for validation of the product against user requirements well before the software is complete, thus enabling the refinement of the design through testing and evaluation.
Black-box testing determines whether the software meets the defined requirements and functions correctly in all scenarios of interest, including edge cases represented by the acceptance criteria. It can reveal weaknesses or areas to improve that may not be apparent from the internal system architecture alone.