What is a defining characteristic of a power test?

A defining characteristic of a power test is its design to allow students to demonstrate their knowledge or skills without time constraints being a significant factor in their performance. When a power test can be completed by at least 80% of the students within one hour, it indicates that the test is appropriately structured to challenge students while providing sufficient time to answer questions without the risk of being rushed. This feature separates it from speed tests, which emphasize how quickly students can respond rather than the accuracy or depth of their understanding.

In contrast, the other options highlight features that do not accurately define a power test. Accessibility to all students regardless of skill level would pertain more to inclusivity and not necessarily to the nature of the test itself. Subjective assessment criteria focus on personal judgments rather than standardized evaluation, which is not specifically a feature of power tests. Lastly, requiring students to work in groups is more indicative of collaborative assessments rather than the characteristics of power tests, which typically assess individual performance.