Use of the design is easy to understand, regardless of the user’s experience, knowledge, language skills, or current concentration level.
3a. Eliminate unnecessary complexity.
3b. Be consistent with user expectations and intuition.
3c. Accommodate a wide range of literacy and language skills.
3d. Arrange information consistent with its importance.
3e. Provide effective prompting and feedback during and after task completion.
You can read all about the other Principles here: