Which of the following statements about usability test plans is true?

A usability test plan is a foundational document created before conducting usability testing. It outlines the objectives, scope, methodology, participants, tasks, and schedule for the testing activities. One of its essential components is the schedule, which details when and how test sessions will occur to ensure proper resource allocation and time management. Including a schedule helps coordinate between test moderators, participants, observers, and stakeholders, making the testing process organized and efficient.

While briefing instructions (Option B) may be related to the usability test, they are typically documented separately or included in participant materials rather than the formal test plan itself. The test plan should be concise and focused; it need not be overly elaborate or lengthy (Option C), as clarity and usability of the plan are more important than length. The results of the test sessions (Option D) are not included in the test plan but rather compiled afterward in a test report or analysis document.

Therefore, the correct statement is that the usability test plan contains a schedule, ensuring a structured timeline for the usability testing activities.