Test Basis
A test basis is the body of information used to identify test conditions and design test cases.
“The body of knowledge used as the basis for test analysis and test design.”
(Definition reproduced from the ISTQB Glossary. Copyright belongs to ISTQB.)
View the complete ISTQB GlossaryWhat is Test Basis?
The test basis includes documents and artifacts such as requirements, user stories, designs, architecture, code, and risk analyses that provide the foundation for testing.
Source information: Defines what should be tested.
Supports test design: Test conditions are derived from the test basis.
Varies by test level: Different levels use different test bases.
Real World Example
A tester is asked to design test cases for a new feature, and the only thing provided is a two-line ticket titled "add discount codes to checkout."
Without a real Test basis — actual business rules about how discount codes stack or expire, a UI mockup, or a conversation with the product owner — anything the tester writes is a guess rather than something derived from a defensible source.
Before designing a single test case, the tester actively assembles the Test basis: requesting the documented rules for discount stacking and expiration, the checkout mockup, and a short conversation with the product owner to close the remaining gaps.
Test cases now specifically cover the discount-stacking rule the ticket title never mentioned, and each one can be traced back to a concrete part of the Test basis if anyone later asks why it exists — something a two-line ticket alone could never support.
Practice Questions
Question 1
A tester is given only a one-line ticket title, "add discount codes to checkout," and asked to write test cases. What is the tester missing before meaningful test design can begin?
Question 2
Which of the following BEST qualifies as part of a test basis for a new checkout feature?
Test your knowledge with real ISTQB-style questions
You’ve learned Test Basis. Test your understanding with topic-specific questions in our Mock Exams.