This one dimensional curve of focus throughout a 2D page will be different on each viewing and for different people. That's why the 2D layout is important beca

This one dimensional curve of focus throughout a 2D page will be different on each viewing and for different people. That's why the 2D layout is important because it can help assist or guide the creation of this path. For many pages there is no fixed "proper" path through the content even though the DOM is necessarily in some order.