Which principle states that information should not be unexpected or unnecessary?

The disclosure principle asserts that information should be presented clearly and transparently, ensuring that users are not taken by surprise by unexpected content or functionality. This principle is integral to creating a user-friendly experience, as users tend to feel more comfortable and confident when they are aware of what to expect. By adhering to the disclosure principle, designers can ensure that all necessary information is readily available and relevant to users, which in turn supports informed decision-making and enhances overall usability.

In contrast, the other principles do not specifically focus on the expectation and necessity of information presented to users. The exemplar principle emphasizes best practices and examples, the object principle relates to the organization of content in a meaningful way, and the front door principle focuses on initial user interactions with a design interface. Although these principles contribute to a positive user experience, they do not specifically address the need for information to be predictable and relevant in the same way that the disclosure principle does.