Description: Error Rate Testing is a set of techniques used in software development to measure the frequency of errors or failures in an application. These tests are fundamental to ensuring software quality, as they help identify and correct issues before the product reaches the end user. The error rate is typically calculated as the number of errors found divided by the total number of opportunities for error, providing a clear and quantifiable metric of software performance. This approach not only helps developers improve the stability and functionality of the application but also contributes to customer satisfaction by reducing the number of failures in daily use. Error Rate Testing is especially relevant in environments where reliability is critical, such as in financial applications, industrial control systems, and medical software. By systematically implementing these tests, development teams can establish a feedback loop that fosters continuous improvement and reduces risks associated with defective software.