In usability testing, how should evaluators conduct their evaluations?

In usability testing, conducting evaluations alone is preferred for ensuring objectivity. When evaluators work individually, they can focus entirely on their observations and analyses without the influence of peers. This method allows them to assess user interactions and experiences with the product or interface based solely on their own perception and understanding of usability principles.

Evaluating alone also minimizes the potential for groupthink, where individuals might alter their opinions to align with others, thus providing a clearer and more unbiased evaluation of the usability of the product. It enables evaluators to document their findings, insights, and immediate reactions to the user experience, which can be more candid and reflective when the evaluation is not influenced by discussions or the presence of others.

While other methods such as group discussions or pairs can provide diverse perspectives and may be useful in different contexts, they do not offer the same level of unbiased observation that individual evaluation can provide in usability testing.