What is the only valid method for measuring a student's ability to perform manipulative skills?

The only valid method for measuring a student's ability to perform manipulative skills is through a performance test. This type of assessment directly observes and evaluates the student's practical application of skills in a hands-on environment. Performance tests allow instructors to assess not only whether students can recall theoretical knowledge but also how effectively they can implement that knowledge in real-life scenarios.

For manipulative skills, which involve executing physical tasks or operations like using equipment or performing specific techniques, direct observation is crucial. It provides the opportunity to see the precision, technique, and overall competency of the student in performing these tasks, ensuring that they are able to meet the required standards of performance in a realistic setting.

In contrast, other assessment methods like subjective tests, written tests, and portfolio assessments do not adequately capture a student's practical abilities. Subjective tests often rely on personal judgment and do not provide a consistent measure of skill execution. Written tests, while useful for gauging theoretical knowledge, do not evaluate physical skills at all. Portfolio assessments might showcase a student's body of work but lack the immediate feedback and performance measurement that a performance test provides. Therefore, using a performance test is essential for accurately gauging manipulative skill proficiency.