ISTQB Updated ISTQB-CTFL Exam Questions and Answers by haaniya

Comprehensive and Detailed In-Depth Explanation:

State transition testing validates valid and invalid state transitions based on defined rules.

D is invalid because it transitions from DIAGNOSTIC MODE directly to EMERGENCY MODE, which is not a valid state change in most systems.

Other options follow valid sequences according to state transition rules.

A typical entry criterion for testing is the availability of testable requirements. Testable requirements provide a basis for designing and executing test cases. Without clear and testable requirements, it is challenging to determine what needs to be tested and to create effective test cases. Entry criteria ensure that the necessary preconditions are met before testing begins, which helps in conducting efficient and effective testing.

Equivalence partitioning is a black-box test design technique where inputs to the software or system are divided into groups that are expected to exhibit similar behavior. For an integer field that should accept values from 1 to 15, the valid equivalence class is 1 through 15. The invalid equivalence classes are numbers less than 1 and numbers more than 15. Therefore, option D, "Less than 1, 1 through 15, more than 15," correctly identifies the valid equivalence class along with the two invalid classes, covering all possible input scenarios for the field. Options A, B, and C either do not accurately capture the valid range or incorrectly specify the range boundaries.

Selecting the right test technique is crucial because different techniques are suited to different types of testing and can significantly increase the effectiveness of the testing process by creating tests that are more likely to find defects. While reducing the number of tests (A) and defining the number of regression cycles (D) are considerations in the testing process, they are not the primary reasons for selecting a test technique. The assertion that the only way to test a software application is by using well-proven test techniques (B) is too restrictive and does not acknowledge the adaptability required in testing to suit different contexts and objectives. Therefore, option C is the most comprehensive reason, as it focuses on the effectiveness and efficiency of testing, leading to the creation of high-quality tests that have a higher chance of finding bugs.