Reading may be characterized as an isolated and
internal task. Document based support for the task of
reading may be available; structure may be articulated,
key words may be highlighted, glosses may be made
available, outlines or summaries may be provided as
navigation aids.
Nevertheless, it is the reader who must monitor the
degree of comprehension with which the reading is
proceeding, who must decide when to make use of any of
the support available. In this sense the reader may be
said to be 'active'; the reader must be monitoring the
reading, and must decide on an acceptable degree of
understanding, must take action when understanding
flags.
Signalling knowledge structure by means such as those
listed in section 2.1 presupposes reader knowledge of the
writing structures (genres) being signalled, or
presupposes that, by being exposed to mention of
structure and signalling of structure, the reader will
develop awareness of the variety and use of knowledge
structures.