In which testing technique does a tester use their knowledge to predict where errors may occur?

The technique where a tester uses their knowledge and experience to anticipate where errors may occur is known as error guessing. This approach relies on intuitive insight gained from past experiences, knowledge of the application, its domain, and typical user behavior or common pitfalls in software development. By identifying sections of the code or application where errors are likely based on this knowledge, the tester can focus their testing efforts more effectively on areas that may be problematic, thereby increasing the likelihood of uncovering defects.

Exploratory testing does involve testers using their skills and information, but it is less focused on prediction and more on simultaneous learning, test design, and execution. Defect-based techniques focus on identifying areas of the system that have had defects in the past to target them for further testing. Equivalence partitioning, on the other hand, is a systematic approach that divides input data into equivalent classes to reduce the number of test cases while ensuring coverage. This method is more structured and does not rely primarily on the tester's intuition to identify potential problem areas.