What is the purpose of usability testing in user-centered interaction design?

Usability testing plays a crucial role in user-centered interaction design by evaluating a product's usability through direct testing with real users. The focus of this method is to observe how users interact with a product, uncovering any challenges they face and assessing how effectively and efficiently they can achieve their goals while using the product.

By conducting usability tests, designers can gather insights into user behavior, preferences, and pain points. This information is vital for refining design elements, enhancing user experiences, and ensuring that the product meets the needs and expectations of its intended audience. The iterative nature of usability testing allows for continuous improvements, making it a fundamental practice in the design process to create user-friendly products.

Other choices, such as creating design specifications, conducting focus group discussions, or gathering subjective user reviews, serve different purposes. While they might provide valuable insights in certain contexts, they do not focus on the practical evaluation of a product's usability through direct user interaction like usability testing does.