ISTQB Updated ISTQB-CTFL Exam Questions and Answers by izabella

The key principles of software testing include: i. Testing shows the presence of defects, not their absence. iv. Defects cluster together. v. Testing is context dependent. vi. Beware of the pesticide paradox. vii. Absence of errors is a fallacy. These principles highlight the importance of recognizing the limitations and context of testing, as well as the potential for repeated tests to become less effective​​.

Comprehensive and Detailed In-Depth Explanation:

Static testing (A) applies to non-executable work products (I), such as requirements or code reviews. It also leads to defect detection (III) and finds defects directly (IV) without executing the software. Options B, C, and D incorrectly associate static testing with performance measurement (II) or dynamic testing aspects (V).

Comprehensive and Detailed In-Depth Explanation:

The primary objectives of testing, as outlined in the ISTQB CTFL v4.0 syllabus, include verifying whether specified requirements are met (A), detecting failures and defects (B), and validating that the test object functions as expected (D). However, "finding errors" (C) is not a direct objective. Errors result from human mistakes, but testing primarily identifies defects, which are flaws in the system that cause failures. Testing aims to reveal defects rather than directly identify errors in the code.

Decision tables are used to model complex decision logic by considering different combinations of conditions and actions. Based on the given decision table for prescribing drug therapy:

Column 1 and Column 3 both result in the same actions (prescribing Amoxicillin).

These columns can be merged because the actions taken do not depend on whether the patient is taking anticoagulant therapy (both are 'T' for this condition).

Thus, combining these columns simplifies the decision table without losing any information.