Finding Non-Local Dependencies: Beyond Pattern Matching

We describe an algorithm for recovering non-local dependencies in syntactic dependency structures. The patternmatching approach proposed by Johnson (2002) for a similar task for phrase structure trees is extended with machine learning techniques. The algorithm is essentially a classifier that predicts a nonlocal dependency given a connected fragment of a dependency structure and a set of structural features for this fragment

General Terms

We describe a pilot on evaluating exploratory search in Wikipedia, the free online encyclopedia. The pilot will be held at CLEF 2006, and brings together both search and navigation, and reading and authoring. Categories and Subject Descriptor

Retrieving Answers from Frequently Asked Questions Pages on the Web

We address the task of answering natural language questions by using the large number of Frequently Asked Questions (FAQ) pages available on the web. The task involves three steps: (1) fetching FAQ pages from the web; (2) automatic extraction of question/answer (Q/A) pairs from the collected pages; and (3) answering users ’ questions by retrieving appropriate Q/A pairs. We discuss our solutions for each of the three tasks, and give detailed evaluation results on a collected corpus of about 3.6Gb of text data (293K pages, 2.8M Q/A pairs), with real users ’ questions sampled from a web search engine log. Specifically, we propose simple but effective methods for Q/A extraction and investigate task-specific retrieval models for answering questions. Our best model finds answers for 36 % of the test questions in the top 20 results. Our overall conclusion is that FAQ pages on the web provide an excellent resource for addressing real users ’ information needs in a highly focused manner

Overview of WebCLEF 2007

This paper describes the WebCLEF 2007 task. The task definition—which goes beyond traditional navigational queries and is concerned with undirected information search goals—combines insights gained at previous editions of WebCLEF and of the WiQA pilot that was run at CLEF 2006. We detail the task, the assessment procedure and the results achieved by the participants. The WebCLEF 2007 task combines insights gained from previous editions of WebCLEF 2005– 2006 [6, 1] and the WiQA 2006 pilot [4, 3], and goes beyond the navigational queries considered at WebCLEF 2005 and 2006. At WebCLEF 2007 we consider so-called undirected informational search goals [5] in a web setting: “I want to learn anything/everything about my topic. ” A query for topic X might be interpreted as “Tell me about X.” In the remainder of the paper we detail the task, the assessment procedure and the results achieved by the participants. 1 Task description As key starting points for defining the WebCLEF task we took several issues into account. First