Designing an Anaphora Resolution Algorithm for Route Instructions

Table of Contents
1. Introduction …….……..……………………………………………….. 5
2. Background and Related Work …….……………………………….. 7
2.1 Route Instructions ………………………………………………………. 7
2.2 Discourse and Anaphoric Reference ……………………………………. 8
2.3. Anaphora Resolution ………………………………………………….. 11
2.3.1 Focusing and Centering Theory ……………………………………… 11
2.3.2 Eckert & Strube – Algorithm ................................................................. 13
2.3.3 The PHORA-Algorithm ..……………………………………………... 18
2.3.4 The THIS-NP Hypothesis …………………………………………….. 20
3. RIAR- and SR-Algorithms ................................................................. 23
3.1 Defining the RIAR-Algorithm ………………………………………... 23
3.2 Discourse Model and Units ……..……………………………………... 24
3.3 Ontology, Lexicon and Selectional Restrictions ………………………. 28
3.4 Salience-List, Implicit S-List and Abstract-Object-List ………………. 35
3.5 Resolution Rules of the RIAR-Algorithm ……………………………... 37
3.6 Here- and There-Anaphors and the SR-Algorithm ….………………... 46
4. Evaluation and Discussion ……………….…………………………. 49
4.1 Evaluation of Eckert & Strube’s-Algorithm on the Development Data .. 49
4.2 Evaluation of the RIAR- and SR-Algorithm on the Development Data ... 51
4.3 Evaluation of the RIAR- and SR-Algorithm on the Test Data ………... 52
5. Conclusions and Further Work ………...………………………….. 57
5.1 Summary ………………………………………………………………. 57
5.2 Open Issues ……………………………………………………………. 58
5.3 Further Work …..………………………………………………………. 61
Bibliography ……………………………………………………………... 65
Appendices ………………………………………………………………..66
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