ISTQB Black-Box Test Design 5

Question 1

A vending machine dispenses items only when the balance equals or exceeds the price and an item is selected. This behavior is BEST modeled by which technique?

Accepted Answer

Decision table testing

Answer

Decision table testing handles combinations of conditions (sufficient balance AND item selected) that jointly determine the outcome.

Question 2

Which of the following BEST describes the purpose of a state transition table compared to a state diagram?

Accepted Answer

It provides a tabular view that makes missing transitions easier to identify

Answer

A state transition table is a tabular representation that makes incomplete or missing transitions (impossible combinations) explicit and easier to identify.

Question 3

A tester discovers that a system behaves correctly for inputs within valid partitions but crashes for a value of 0 that was not explicitly identified as a boundary. What does this suggest?

Accepted Answer

The test design missed an invalid equivalence class or boundary

Answer

The crash reveals that 0 was an unconsidered boundary or invalid partition that should have been included in the test design.

Question 4

Which term describes a pair of states connected by a transition in a state machine, used as the basis for 1-switch coverage?

Accepted Answer

Transition pair

Answer

1-switch coverage requires exercising all valid sequences of two consecutive transitions (transition pairs) through intermediate states.

Question 5

When combining black-box techniques, which combination is MOST commonly used to test a numeric input field with distinct behavioral ranges?

Accepted Answer

Equivalence partitioning + boundary value analysis

Answer

EP identifies the distinct valid and invalid ranges, and BVA then tests the critical boundary values within and between those ranges.

ISTQB - International Software Testing Qualifications Board Practice Test

ISTQB - International Software Testing Qualifications Board Practice Test

ISTQB Black-Box Test Design 5