Black-Box Test Design Flashcards

A password field requires 8 to 16 characters. Using 3-value BVA, which set of test values is complete?

Answer: 7, 8, 9, 15, 16, 17

3-value BVA tests the value below, at, and above each boundary: 7, 8, 9 for the lower boundary and 15, 16, 17 for the upper boundary.

Which statement about invalid equivalence partitions is CORRECT?

Answer: Each invalid partition should be covered by a separate test case

Each invalid partition should have its own test case to avoid masking errors, as multiple invalid inputs in one test may hide failures.

In a state machine with 4 states and 6 transitions, what is the minimum number of tests needed for transition coverage (0-switch)?

Answer: 6

0-switch coverage requires exercising each transition at least once, so the minimum is equal to the number of transitions (6).

A use case has 3 alternative flows in addition to the basic flow. How many test scenarios are minimally required to achieve basic use case coverage?

Answer: 4

Basic use case coverage requires at least one test for the basic flow plus one for each alternative flow, totaling 4 scenarios.

Which of the following is NOT a black-box test design technique according to ISTQB?

Answer: Statement coverage testing

Statement coverage is a white-box (structural) technique; the others are black-box techniques based on specifications.

When is decision table testing LEAST appropriate?

Answer: When a system has a single input with a continuous numeric range

Decision tables are least suitable for single continuous ranges; boundary value analysis or equivalence partitioning is more effective there.

A tester identifies 3 equivalence classes: EC1 (valid), EC2 (invalid-low), EC3 (invalid-high). She writes one test for EC1, one for EC2, and one for EC3. Which coverage has she achieved?

Answer: Full equivalence partition coverage

Covering at least one value from every identified equivalence class (valid and invalid) satisfies equivalence partition coverage.