Boundary value analysis
A grading system accepts whole-number scores from 2 to 53 and rejects anything else.
Practice
Test design practice questions
Exam-style questions on the four black-box techniques and on statement and branch coverage, generated fresh each time, so you practise the method rather than memorising answers. Every wrong answer tells you which mistake leads to it.
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How the questions are made
Each question is a scenario with random numbers, drawn from a seed, so there are far more of them than anyone could memorise, and “Copy link to this question” gives a link that always brings back the one on screen. The answer is computed by the same code as the site’s boundary value, decision table and state transition tools, which follow the definitions in section 4.2 of the ISTQB Foundation Level syllabus, version 4.0. Our tests work out every answer a second way, straight from the question’s wording, for thousands of seeds per topic.
Statement and branch coverage questions use short programs with IF and IF-ELSE only, each IF testing its own variable, and no loops. Loops are left out on purpose: how often a loop runs changes the minimum number of tests, and that is where exam-style questions most often have two defensible answers. For every program, our tests list every path through it and find the smallest set of paths that covers everything by trying them all, and the answer has to match. The wrong answers include the cyclomatic complexity, decisions plus one, which is often mistaken for the minimum number of tests for branch coverage. It isn’t: it’s an upper bound.
The wrong answers aren’t random numbers. Each one is what a specific mistake produces: counting only the valid partitions, three values per boundary instead of per boundary value, dividing by every cell of the state table. When you pick one, the feedback names the mistake, which is usually the thing worth learning.
What this is not
These are not questions from any ISTQB exam, and this site has no connection with ISTQB or any exam provider. They cover the calculations in the test techniques chapter, the part where practice helps most; the exam also asks about everything else in the syllabus. Older question banks often use definitions from before version 4.0, so if an answer here disagrees with one you’ve seen elsewhere, check which syllabus it was written for.
To see the four techniques applied to one real checkout, with the results we observed, read black-box test design techniques on one real checkout.