Under what circumstance can an instructor or student instructor practice on patrons?

The correct answer indicates that practice on patrons is permitted solely for demonstration purposes. This is a standard practice in cosmetology education, where instructors or student instructors may showcase techniques or services to illustrate methods and skills to students. Demonstration provides an opportunity to showcase proper procedures and enhance the educational experience of the students.

In a classroom setting, demonstrations are typically structured to ensure that the skills being taught are conveyed effectively while minimizing risks to the patron. This controlled environment allows students to learn by example, observing the application of techniques in real-world scenarios, which is crucial for their training.

The other options present various circumstances that do not align with the established rules governing practice on patrons. Practicing for personal experience would not be aligned with the educational framework required in a professional setting. Conducting practice exams typically occurs in a testing environment rather than live demonstrations on patrons. Similarly, while supervision is integral to teaching, the specific context of practicing on patrons is more accurately captured by the guidelines for demonstration rather than ongoing supervision.