Which usability testing method aims to measure metrics like effectiveness and efficiency?

The correct answer is summative usability test because this method is specifically designed to evaluate the performance of a product in terms of measurable metrics such as effectiveness (the degree to which users achieve their goals) and efficiency (the resources expended in relation to the accuracy and completeness with which users achieve their goals). In a summative usability test, researchers often gather quantitative data, such as task success rates and time on task, allowing for objective assessments of the usability of a system.

This testing is usually conducted at the end of the design process to confirm whether the product is meeting user needs and to provide insights into areas that may require improvement before final release. By focusing on metrics, summative testing can help in comparing different design iterations or assessing the product against standards and benchmarks in usability.

Other methods, like formative usability tests, are typically more iterative and aimed at identifying and solving usability issues during the design process rather than measuring overall effectiveness and efficiency. Exploratory usability tests focus on gathering insights into user behavior and discovering potential usability problems without the strict quantitative measurements. Comparative usability tests involve comparing different products or versions but do not inherently focus on measuring effectiveness and efficiency.