A black-box testing technique that, because defects tend to cluster at the boundaries between equivalence classes, tests the values immediately on both sides of each boundary (for example 0, 1, 100 and 101 when 1 to 100 is accepted). It is good at finding errors such as confused comparison operators.
Japanese name: 境界値分析
Boundary value analysis appears in 3 practice questions across 1 topic, including Software Development and Project Management.
Conditional branches in programs are prone to errors such as confusing '<' with '<=' or '>' with '>=', or being off by one in an array index, and the effect appears only at boundary values. For example, if the specification says 'warn at 85 °C or higher' but the code says if (t > 85), it behaves as specified at 84 °C and 86 °C and fails to warn only at 85 °C. Testing only the middle value of each class with equivalence partitioning does not find such errors.
When integer inputs from 1 to 100 are accepted, 0 and 1 are chosen at the lower boundary and 100 and 101 at the upper boundary. A finer variant tests each boundary value and both of its neighbors (0, 1, 2 and 99, 100, 101). When there are several categories, such as fee categories, values on both sides of every boundary where the category changes are chosen. For decimal inputs, the neighboring value is determined by the resolution set in the specification (such as steps of 0.1).
Embedded software has many numerical boundaries in its specification, such as thresholds on ADC readings, the point where a timer counter wraps from its maximum to 0, the point where a buffer becomes exactly full, and the maximum packet length of a communication protocol. Calculation errors are likely around the overflow from 255 to 0 for an 8-bit counter, or the boundary between 32,767 and −32,768 for a 16-bit signed integer. Such boundaries are identified from both the numbers in the specification and the ranges of the data types.
Answer: B. 17, 18, 64, 65
Because defects tend to cluster at the boundaries between equivalence classes, boundary value analysis tests the values immediately on both sides of each boundary. At the child/adult boundary 17 and 18 are chosen, and at the adult/senior boundary 64 and 65, giving the four values 17, 18, 64 and 65. Errors such as writing '<' instead of '<=' in a condition may not be found by testing only one side of a boundary. 10, 40 and 90 are equivalence-partitioning values chosen as representatives of each category, and they cannot check errors at the boundaries.
They are usually combined. Equivalence partitioning divides the inputs into classes and tests a representative of each, and boundary value analysis adds tests on both sides of the class boundaries. Equivalence partitioning alone reduces the number of tests but tends to miss errors at the boundaries.
It chooses values from the boundaries of the ranges written in the specification, so it is a black-box testing technique. However, some boundaries, such as array sizes and data type ranges inside the implementation, are not written in the specification, so values are sometimes added after looking at the source code.
Because defects tend to cluster at the boundaries between equivalence classes, boundary value analysis tests the values immediately on both sides of each boundary.
A program sets the admission fee by age (an integer of 0 or…Black-box testing treats the test object as a box whose contents cannot be seen and creates test cases from the specification alone; its techniques include equivalence partitioning, boundary value analysis, cause-effect graphs and decision tables.
Which describes black-box testing?Testing values that include the boundary itself in this way is the idea of boundary value analysis.
The specification says 'issue a warning if the temperature …As an Amazon Associate I earn from qualifying purchases.
Black-box testing Equivalence partitioning White-box testing Agile development Branch coverage CI/CD (continuous integration and continuous delivery) Critical path method (CPM) Earned value management (EVM) Scrum SLA (service level agreement)