"One Apparently Unresolved Problem With Hasan's Technique"

Martin (1992: 419, 422):

One apparently unresolved problem with Hasan's technique is that there is often considerable overlap between some strings and chains, especially where pronouns are lexically rendered. […] For reasons that are not made explicit however strings and chains do not overlap in Hasan's diagrams, possibly because reference chains are given priority, with lexical strings composed only of items not already included in reference chains.  A strategy for resolving the problem of overlapping strings and chains will be proposed during the analysis of chain interaction in [6:33] below.

Blogger Comments:

[1] Martin does not explain — here or elsewhere — why he regards overlapping 'strings and chains' as a problem.  He merely asserts that it is.

To be clear, only Martin's model has (lexical) strings and (reference) chains.  On Hasan's model, the grammatical cohesive device of reference and the lexical cohesive devices involve different types of cohesive chains.  Grammatical reference involves identity chains, whereas lexical cohesion involves similarity chains.

[2] When serving as a comment Adjunct, apparently signals 'presumption: hearsay'.

[3] The overlapping of Martin's lexical strings and reference chains arises from Martin's discourse semantic system of identification — 'the semantics of reference' — confusing two distinct types of cohesion, reference and lexical cohesion, largely as a consequence of confusing the referent with the system of reference.  See previous critiques here, here, here, here and here.