2011 Volume 18 Issue 1 Pages 31-56
We propose the method of the discourse structure analysis based on the centering theory and the domain knowledge. We enhanced the centering theory to utilize it for the analysis of dependency relation among sentences. Moreover, object knowledge among objects such as entire-part relation, parent-child relation, object-attribute relation, resemblance are extracted from the co-occurrence dictionary and concept dictionary in EDR electronic dictionary, and are used for the decision of the functional relation between sentences. We defined the discourse structure tree to show the transition of the topic in the discourse. Here, the sentence punctuated by the period makes a node, and each sentence node has only one parent node. Moreover, nine kinds of connection relationships between sentences: DETAIL, EXPLICATE, CONTRAST, CAUSE-RESULT, TRANSITION, CONVERSION, PARALLEL, EXAMPLE and QUESTION-RESPONSE are given to each arc between sentence nodes. Next, we have developed 36 rules to evaluate the possibility of the relation between sentences being each one of the nine kinds of relation types. These rules are applied to each arc, and the relation label which obtained the highest score is given to the arc. The evaluation experiment shows the accuracy of 82% and 81% respectively in deciding the connection destination and the relationship label.
