2.4.4 PARNASSUS
Even though PARNASSUS concentrates on language processing at the paragraph level rather than specifically targeting sentence-level stylistics, the system shares a design objective of STASEL in focusing on the problem of teaching students how to write effective sentences, appropriate to the context in which they are written. Unlike STASEL, however, which concentrates on the implementation of a thorough linguistic component that is used to feed the stylistic portion of the expert module of the IT’S, the design of PARNASSUS emphasizes the pedagogical considerations as well as the rhetorical portion of the expert module. In Section 2.2, we used the pedagogical principles that were outlined for PARNASSUS to give rhetorical problems without the support of a strong linguistic component, severely restricts the linguistic processing capabilities of the prototype and may eventually force Neuwirth, her own opinion, to rethink her original strategy.
PARNASSUS is designed to provide students with some understanding of the concepts of paragraph coherency and emphasis." The student is asked to read a paragraph that lacks coherence and emphasis, and to produce a revision of it in which the sentences have been made more effective by choosing alternative systaltic patterns. (The exercises are designed so that syntactic strategies suffice to fix the paragraph problem.) PARNASSUS compares the student's revision to a set of possible revisions previously "rated" according to a model of the rhetorical goals characteristic of discourse strategy. The comparison is performed by simple pattern-matching.
Incapable of "understanding" the student revision let alone generating a formal representation of its content PARNASSUS has to simplify the analysis by constraining the student's response and limiting its coverage to a small set of possible sentence structures. Neuwirth acknowledges that parsing techniques, rather than pattern-matching heuristics, may be necessary to enhance the scope of the program [Neu89, pp.55-56].