Which testing technique is targeted at specific types of defects?

The defect-based test design technique is focused on identifying specific types of defects that have historically occurred in similar applications or systems. This technique involves analyzing defects that have been previously found to understand their characteristics and originating conditions. By concentrating on known defect types, defect-based testing helps testers create effective test cases aimed at exposing those same or similar issues in the current development cycle.

This specialized approach is advantageous in environments where specific defects are more likely to influence the overall quality or functionality of the software. It enables testers to optimize their efforts by targeting areas of the application that have previously been problematic or that are at higher risk for defects, thus increasing overall testing efficiency and effectiveness.

In contrast, the other options, such as functional testing, boundary value analysis, and regression testing, do not specifically target known defect types. Functional testing evaluates the software against functional requirements without focusing on defect history. Boundary value analysis is a specific testing technique that focuses on values at the boundaries between different classes of input, not on historical defects. Regression testing, while important, is primarily concerned with verifying that previously developed and tested software still performs after changes, rather than targeting specific defect types.