Evidence, defects, and test objectives | ISTQB Foundation: testing and quality decisions

Concept and mechanism

Testing helps produce information about quality and risk. A passing execution demonstrates the observed result under the conditions used; it does not prove that every behavior is correct. A human error can introduce a defect in a work product; when that defect manifests during execution, a failure may occur. Testing and debugging have different purposes: identifying and evaluating problems is not the same as locating and correcting the cause. Quality is a team responsibility, and independent perspectives help expose assumptions without replacing collaboration.

Guided application

In a fictional transfer service, a domestic suite does not automatically provide international coverage. Link requirements and risks to conditions, cases, results, and defects. When a rule changes, these links help select affected work. If the same tests no longer reveal new issues, review data and objectives rather than merely increasing repetition. Historical defect concentration helps guide effort but does not justify ignoring new components. A product without known failures may still fail to satisfy the user’s need.

IN PRACTICE

An incorrect fee originates from a misinterpreted rule. Testing observes the wrong amount; investigation identifies the code condition and the team clarifies the original rule.

Common pitfalls

Using pass rate as proof of coverage; assigning all quality responsibility to testers; keeping tests unchanged when the product changes.

Related topics: Lifecycle testing and regression · Review before code

Take this idea with you

Communicate what was exercised, under which conditions, and which risk remains without evidence.

Create account

Reference: ISTQB CTFL syllabus v4.0.1 · CTFL v4.0; syllabus v4.0.1 (2024-09-15)