  The semantic analysis of documents is a domain of intense research at
present. The works in this domain can take several directions and touch several
levels of granularity. In the present work we are exactly interested in the
thematic analysis of the textual documents. In our approach, we suggest
studying the variation of the theme relevance within a text to identify the
major theme and all the minor themes evoked in the text. This allows us at the
second level of analysis to identify the relations of thematic associations in
a textual corpus. Through the identification and the analysis of these
association relations we suggest generating thematic paths allowing users,
within the frame work of information search system, to explore the corpus
according to their themes of interest and to discover new knowledge by
navigating in the thematic association relations.
