NoviceInterface elements are sometimes in unexpected places or the layout is too squished or too spread out for comfort.
CompetentInterface is laid out following conventions to enhance usability and has an appropriate density for the medium and content.
ProficientInterface layout is flawless—no doubts about what does what, or where to look for certain actions. Alignment is carefully considered throughout.
ExpertInterface is designed with full flexibility in mind, and is not designed to be a “fixed size” layout. How the layout adapts to different amounts of content has been considered throughout.