Designing User Interfaces
http://www.hcirn.com/tutor/ui/index.php

HCIRN
2001

Abstract:

In the discussion of interface components we sometimes found it difficult to keep logical interface components separate from toolkit interface components. For example, a label is a logical interface component that describes another component. However, a label is also a toolkit interface component that is used to display non-interactive text and graphics. As such, a label may by used for other functions besides describing other components. For example, a label may be used to create a section header or to display some icons. Wherever possible, we tried to make the distinction between logical and toolkit interface component explicit.