A product owner states that a tester's role is to catch all bugs before the end of each iteration. Which testing principle responds to this statement?

The statement made by the product owner can be related to the testing principle that emphasizes that testing shows the presence of defects. This principle suggests that no matter how thorough the testing process is, it can only demonstrate that defects are present; it cannot prove that a product is entirely free of defects.

It's important to understand that the role of a tester is not solely to catch all bugs but to provide information about quality and risk through various testing activities. The assertion that all defects must be caught before the end of each iteration places an unrealistic expectation on testing, as it fundamentally contradicts the nature of software testing. The aim of testing is to uncover defects rather than to guarantee their complete absence.

Considering this principle helps testers and stakeholders appreciate that defects may still exist despite thorough testing, which aligns with the reality of software development, where complexity and unforeseen issues can lead to bugs that testing may not reveal.