Some words on Affordance
When an object looks like it might let you do something, such as click it or drag it, we say it “affords” performing that action. Here’s some specific design advice:
- Follow conventions whenever possible. Reuse UI concepts and controls that people already know;
- Use pseudo-3D shading and drop shadows to make things look “raised”;
- When the mouse pointer hovers over items that can be clicked or dragged, turn the pointer into something different, such as a finger or a hand;
- Use tool tips, or some other descriptive text, to tell the user what the objects under the mouse pointer do. If you don’t need them, that’s great - you have a self-describing design - but many users expect tool tips anyway.
cited from Jenifer Tidwell’s book “Designing Interfaces,2nd Edition”