What are the principles that designers must consider besides logic?

Good design significantly enhances the usability of a product. It makes the product intuitive and easy to use, eliminating the need for detailed instructions or guidance. It ensures that the product's purpose is clear and that it can be used effectively and efficiently. When a product is well-designed, users can understand and use it without confusion or difficulty, which improves their overall experience and satisfaction.

The principles of psychology, cognitive science, and art can be applied in product design by understanding how users interact with and perceive objects. This involves creating intuitive designs that indicate their function and use, such as making a pillar visible to indicate which side of a door is attached to a hinge. Overly complex designs can confuse users and defeat the purpose of the design.