Retest

Retest is the act of performing a test again after an initial result, used to verify accuracy, assess changes, or confirm a repair. It appears in domains such as software development, education, medicine, and scientific research. A retest usually aims to reduce measurement error and increase confidence in the outcome, under controlled conditions.

In software testing, retest re-executes specific test cases that previously failed, after a defect has been fixed, to confirm the issue is resolved. It uses the same inputs and environment as the original test. Retest is distinct from regression testing, which checks for unintended effects across the system after changes.

In education, a retest or retake allows a student to attempt an assessment again to improve a grade or demonstrate mastery. Institutions set rules on eligibility, timing, and scoring. Retests address measurement error but can introduce scheduling and fairness considerations.

In medical and laboratory settings, retesting is conducted when results are inconclusive, suspect, or when monitoring progression or response to treatment. Repeating the test with the same method and sample handling helps verify results and inform decisions, though delays and additional costs may occur.

Design and interpretation: Retesting informs reliability estimates, including test-retest reliability. Key factors include timing, methodology, and consistency. While retesting can improve precision, it can also introduce practice effects or resource burdens, so it is used where the benefits outweigh the costs.