Which of the following is a qualitative evaluation method?

User trials are considered a qualitative evaluation method because they focus on understanding the experiences, perceptions, and feedback of users interacting with a product. This approach allows for in-depth insights into user satisfaction, usability, and emotional responses, which can be gathered through interviews, observations, and open-ended questions.

Qualitative evaluations typically emphasize rich, descriptive data that provides context and meaning to users' experiences, rather than just numerical or statistical analysis. By utilizing user trials, designers can gather subjective information that helps to inform design decisions, improving the overall user experience and ensuring that the product meets the needs of its target audience.

In contrast, other methods like sales data analysis, comparing product specifications, and performance metrics are primarily quantitative. They rely on measurable data and specific criteria, which may not capture the nuances of user interaction or emotional responses.