What is error guessing?

Error guessing is a testing technique that involves making educated guesses about where defects may exist in a system based on the tester's experience and intuition. By understanding common pitfalls and areas where developers are likely to make mistakes, a tester can focus their efforts on those areas, effectively increasing the chances of uncovering defects. This approach leverages the tester's skills and knowledge about the application, the domain, and previous experiences with similar systems.

The other options describe different concepts that are not aligned with the essence of error guessing. Assessing defect metrics pertains to the measurement and analysis of defects after they have been identified, which does not involve making proactive guesses about where to find them. Verifying that all error paths have been coded relates more to ensuring complete and correct coding rather than investigating potential errors. A planning technique for anticipating schedule variances focuses on project management rather than on identifying specific areas of potential defects in the software. This reinforces that error guessing is distinctly about anticipating where defects might be present based on insight rather than established metrics or development processes.