  Morris and Hirst present a method of linking significant words that are about
the same topic. The resulting lexical chains are a means of identifying
cohesive regions in a text, with applications in many natural language
processing tasks, including text summarization. The first lexical chains were
constructed manually using Roget's International Thesaurus. Morris and Hirst
wrote that automation would be straightforward given an electronic thesaurus.
All applications so far have used WordNet to produce lexical chains, perhaps
because adequate electronic versions of Roget's were not available until
recently. We discuss the building of lexical chains using an electronic version
of Roget's Thesaurus. We implement a variant of the original algorithm, and
explain the necessary design decisions. We include a comparison with other
implementations.
