Towards a German frame based QA System Frame Semantics and QA - PowerPoint PPT Presentation

Towards a German frame based QA System Frame Semantics and QA Andrei Beliankou LDV/CL, Trier July 28, 2010

Welche Farbe hat eine Maracuja? What colour is passion fruit? A. Beliankou (Trier) QA July 28, 2010 2 / 26

Outline What is QA? 1 IR and QA: short comparison Definition Approaches to Answering Questions 2 Related work on QA using SR 3 Frame based formalism 4 Tools 5 A. Beliankou (Trier) QA July 28, 2010 3 / 26

What is QA? Douglas Adams and QA A. Beliankou (Trier) QA July 28, 2010 4 / 26

What is QA? Douglas Adams and QA The Ultimate Question of Life, the Universe, and Everything A. Beliankou (Trier) QA July 28, 2010 4 / 26

What is QA? Douglas Adams and QA The Ultimate Question of Life, the Universe, and Everything A. Beliankou (Trier) QA July 28, 2010 4 / 26

What is QA? IR and QA: short comparison A Typical Search Engine A. Beliankou (Trier) QA July 28, 2010 5 / 26

What is QA? IR and QA: short comparison A Typical Search Engine A. Beliankou (Trier) QA July 28, 2010 6 / 26

What is QA? IR and QA: short comparison A Typical Search Engine A. Beliankou (Trier) QA July 28, 2010 7 / 26

What is QA? IR and QA: short comparison Social QA A. Beliankou (Trier) QA July 28, 2010 8 / 26

What is QA? IR and QA: short comparison Well grounded QA Systems A. Beliankou (Trier) QA July 28, 2010 9 / 26

What is QA? Definition What is QA? Question Answering Question Answering (QA) is an interactive human computer process that encompasses understanding a user information need, typically expressed in a natural language query; retrieving relevant documents, data or knowledge from selected sources; extracting, qualifying and prioritizing available answers from these sources; and presenting and explaining responses in an effective manner. Maybury [2004, p. 3] A. Beliankou (Trier) QA July 28, 2010 10 / 26

What is QA? Definition What is QA? Question Answering Question Answering (QA) is an interactive human computer process that encompasses understanding a user information need, typically expressed in a natural language query; retrieving relevant documents, data or knowledge from selected sources; extracting, qualifying and prioritizing available answers from these sources; and presenting and explaining responses in an effective manner. Maybury [2004, p. 3] A. Beliankou (Trier) QA July 28, 2010 10 / 26

What is QA? Definition What is QA? Question Answering Question Answering (QA) is an interactive human computer process that encompasses understanding a user information need, typically expressed in a natural language query; retrieving relevant documents, data or knowledge from selected sources; extracting, qualifying and prioritizing available answers from these sources; and presenting and explaining responses in an effective manner. Maybury [2004, p. 3] How can we understand questions automatically? A. Beliankou (Trier) QA July 28, 2010 10 / 26

What is QA? Definition What is QA? Question Answering Question Answering (QA) is an interactive human computer process that encompasses understanding a user information need, typically expressed in a natural language query; retrieving relevant documents, data or knowledge from selected sources; extracting, qualifying and prioritizing available answers from these sources; and presenting and explaining responses in an effective manner. Maybury [2004, p. 3] How can we understand questions automatically? What is the technique for extracting relevant information? What should we do if there is no out of the box answer? A. Beliankou (Trier) QA July 28, 2010 10 / 26

What is QA? Definition What is QA? Question Answering Question Answering (QA) is an interactive human computer process that encompasses understanding a user information need, typically expressed in a natural language query; retrieving relevant documents, data or knowledge from selected sources; extracting, qualifying and prioritizing available answers from these sources; and presenting and explaining responses in an effective manner. Maybury [2004, p. 3] How can we understand questions automatically? What is the technique for extracting relevant information? Can we measure the information weight of an answer? What should we do if there is no out of the box answer? A. Beliankou (Trier) QA July 28, 2010 10 / 26

What is QA? Definition What is QA? Question Answering Question Answering (QA) is an interactive human computer process that encompasses understanding a user information need, typically expressed in a natural language query; retrieving relevant documents, data or knowledge from selected sources; extracting, qualifying and prioritizing available answers from these sources; and presenting and explaining responses in an effective manner. Maybury [2004, p. 3] How can we understand questions automatically? What is the technique for extracting relevant information? Can we measure the information weight of an answer? What should we do if there is no out of the box answer? What is the best way to show up the answers? A. Beliankou (Trier) QA July 28, 2010 10 / 26

What is QA? Definition Prototype of a QA System A. Beliankou (Trier) QA July 28, 2010 11 / 26

Approaches to Answering Questions Alignment of Question and Answers Die Shale ist bei den bis hühnereigroßen, kugeligen bis ovalen Früchten der f. edulis braun-violett und wird im Reifezustand runzlig. A. Beliankou (Trier) QA July 28, 2010 12 / 26

Approaches to Answering Questions Alignment of Question and Answers Die Shale ist bei den bis hühnereigroßen, kugeligen bis ovalen Früchten der f. edulis braun-violett und wird im Reifezustand runzlig. Welche Farbe hat die Maracuja-Frucht? Wie sieht die Maracuja-Beere aus? Wie ist das Aussehen der Maracuja? Wie ist die Farbe der Maracuja? Was für eine Farbe hat die Maracuja? * Wie erscheint die Maracuja? A. Beliankou (Trier) QA July 28, 2010 12 / 26

Approaches to Answering Questions Alignment of Question and Answers Die Shale ist bei den bis hühnereigroßen, kugeligen bis ovalen Früchten der f. edulis braun-violett und wird im Reifezustand runzlig. Welche Farbe hat die Maracuja-Frucht? Wie sieht die Maracuja-Beere aus? Wie ist das Aussehen der Maracuja? Wie ist die Farbe der Maracuja? Was für eine Farbe hat die Maracuja? * Wie erscheint die Maracuja? Main Question!!! How do we know, that these questions do correspond to this answer? A. Beliankou (Trier) QA July 28, 2010 12 / 26

Approaches to Answering Questions Is it an Alignment Problem? How should we treat "not alignable" tokens? Where can we get large aligned parallel corpora of Questions and Answers? A. Beliankou (Trier) QA July 28, 2010 13 / 26

Approaches to Answering Questions Is it an Alignment Problem? How should we treat "not alignable" tokens? Where can we get large aligned parallel corpora of Questions and Answers? Hm, we need some kind of intermediate semantic representation. . . A. Beliankou (Trier) QA July 28, 2010 13 / 26

Approaches to Answering Questions Architecture of a QA System A. Beliankou (Trier) QA July 28, 2010 14 / 26

Related work on QA using SR Frames Definition Frame characterizes a small abstract „scene“ or „situation“, so that to understand the semantic structure of the verb it was necessary to understand the properties of such schematized scenes. [Ruppenhofer et al., 2006] (cf. Tannen [1993] for a good overview) A Theory of the semantic case, developed by Ch. Fillmore [Fillmore, 1985]; Semantic Frames are powerfull enough, but the parser implementation is still relatively easy [Gildea and Jurafsky, 2002, Lluís and Màrquez, 2008]; Nowadays there are many works on SR for QA, but they describe this formalism only for parsing answers and only as an additional technique [Shen and Lapata, 2007, Pizzato and Molla, 2008, Narayanan and Harabagiu, 2004]. A. Beliankou (Trier) QA July 28, 2010 15 / 26

Related work on QA using SR Example of a Frame Frame Title: Commerce Buy Frame Evoking Element: Kauf Frame Elements (Roles): Buyer, Goods Frame Description: These are words describing a basic commercial transaction involving a buyer and a seller exchanging money and goods, taking the perspecitive of the buyer. A. Beliankou (Trier) QA July 28, 2010 16 / 26

Frame based formalism Frame based formalism Figure: from the FEAST Talk by Hagen Fürstenau, Nov 26, 2008 A. Beliankou (Trier) QA July 28, 2010 17 / 26

Frame based formalism Enchanced Architecture A. Beliankou (Trier) QA July 28, 2010 18 / 26

Frame based formalism Parsing Answers A. Beliankou (Trier) QA July 28, 2010 19 / 26

Frame based formalism Answering simple Questions A. Beliankou (Trier) QA July 28, 2010 20 / 26

Frame based formalism Inference based QA A. Beliankou (Trier) QA July 28, 2010 21 / 26

Tools Tools & Ressources Software Tools: YANSER - Yahoo! ANSwers gatherER; SHALMANESER - SHALlow seMANtic parSER [Erk and Padó, 2006]; SALTO - SALsa TOol [Burchardt et al., 2006]; TigerRegistry & TigerSearch [Lezius, 2002]; TreeAligner [Lundborg et al., 2007]. Corpora: TIGER; FrameNet; SALSA. A. Beliankou (Trier) QA July 28, 2010 22 / 26