In order to extract some salient sentences from the article as definition summaries, we will build a summarization model that describes the relations between the sentences, where both textual and structural features are considered.

Wikipedia’s special structural features , such as wiki links, infobox and outline, reflect the hidden human knowledge.

Based on the performance of EDCL for TREC—QA definition task listed in Table 5, we observe that: (i) When EDCL considers wiki concepts and structural features such as outline and infobox, its F—scores increase significantly (Run 3 and Run 4).

The rest of this paper is organized as follows: In the next section, we discuss the background of summarization using both textual and structural features .

Different from free text and general web documents, wiki articles contain structural features , such as infoboxes and outlines, which correlate strongly to nuggets in definition TREC—QA.

By integrating these structural features , we will generate better RP measures in derived topics which facilitates better priority assignment in local topics.