Some Foundational Linguistic Elements for QA Systems: an Application to E-government Services Farida Aouladomar JURIX 05 9/11/05.

Présentation au sujet: "Some Foundational Linguistic Elements for QA Systems: an Application to E-government Services Farida Aouladomar JURIX 05 9/11/05."— Transcription de la présentation:

1 Some Foundational Linguistic Elements for QA Systems: an Application to E-government Services Farida Aouladomar JURIX 05 9/11/05

2 Objective problematics of procedural texts for answering procedural questions on the web governments increasingly offer online services to their citizens. ex: How can I get the french citizenship? Semantics and structure of procedural text answers to procedural questions are structures where to unify questions and parts of the procedural texts give a complete and appropriate response

3 Advanced Question – Answering Framework QA Systems for factoid questions : InferenceWEB (McGuinness, 04), JAVELIN (Nyberg and al, 03), Mulder (Kwok and al, 00), WEBCOOP (Benamara, 04) Non-factoid questions: comparison, procedural, opinion, causal, etc. How-questions within a cooperative environment

4 How to get a passport ? Response Question analysis Procedural Question? Search engine n texts Filtering 1 Procedural texts ? Annotation Grammar Filtering 2 Unification

5 Overview Procedural questions Grammar of procedural discourse - syntactic structure - linguistic marks Questionability and responses

6 Procedural questions (1) Procedural questions = questions introduced by « comment » - Comment vas-tu ? - Comment dit-on maison en espagnol ? - Comment est mort John? - Comment on mange le couscous au Maroc ? - Comment payer mon billet davion ? - Comment changer une roue ? - Comment créer une entreprise ?

7 Procedural questions (2) Other forms of procedural questions : –Forms in : « que faire … », « quel + être + proposition » … Ex: que faire pour obtenir un visa ?, quelles sont les démarches à effectuer pour obtenir un visa pour lInde? quelle est la procédure pour obtenir la nationalité belge ?

8 – The elliptical use of « comment » : key words Ex: trouver un avocat, déposer une plainte, inscription sur liste électorale … – Lexical inference : Ex : jai perdu mon passeport Questions expecting an answer of procedural type : Ex: est-il possible davoir la double nationalité ? Procedural questions (3)

9 Overview Procedural questions Grammar of procedural discourse - syntactic structure - linguistic marks Questionability and responses

10 Sequences of instructions operating over a specific set of entities in order to reach a goal. Goals & subgoals = skeletal structure of procedural texts Group of texts : cooking receipes, maintenance manuals, assembly notices, directions for use, teaching texts, medical notices, social behavior recommendations, advice texts, savoir-faire guides, itinerary guides, architectory plans, musical scales, legislation, court decisions, legal guidelines & procedures, etc. Corpus : identify textual elements of procedural texts for the answer process. Procedural texts

11 Discursive Structure - Corpus (1) Structure analysis of procedural texts : - Corpora analysis : method based on how queries on the web and on manual enrichment Questions classification Nb of procedural texts from queries inventory Nb of added procedural texts Total number of texts in our corpus Communication / advices / e-government 480 Technical domain computer science assembly texts 302050 Health 369 Receipes 010 Rules 077 total 8143124

12 Discursive Structure Grammar (2) Text title, (summary), (warning)+, (pre-requisites)+, (picture) + < objective. Summary title+. Pre-requisites list of objects, (instruction sequences). Instruction sequences instseq < {connector} < instruction sequences / instseq. Objective {goal}< (warning), (picture), (pre- requisites), instruction sequences+ / objective

13 Grammar (3) Instruction (iterative expression), action, (goal) (argument)+, (reference),(picture)+, (warning) Imperative linear sequence instruction < {temporal mark}, imperative linear sequence / instruction. Optional sequence optionality expression, imperative linear sequence. Instruction sequence imperative linear sequence / optional sequence / alternative sequence / imperative co-temporal sequence.

14 Imperative co-temporal sequence imperative linear sequence < co-temporal mark < imperative co-temporal sequence / instruction. Instruction (iterative expression), action, (goal) (argument)+, (reference), (picture)+, (warning) Alternative sequence (conditional expression), (argument), imperative linear sequence, (alternative-opposition mark) < instseq / (conditional expression, instseq). Grammar (3)

15 summary title Texte title, (summary), (warning)+, (pre-requisites)+, (picture) + < objective. warning Objective

16 Objective {goal}< (warning)+, (picture)+, (pre-requisites), instruction sequences+ / objective goalwarningInstruction sequences Pre-requisites

17 Imperative linear sequence instruction < (temporal mark) < imperative linear sequence / instruction La premiere étape consiste à ouvrir entièrement le boîtier, puis de le placer à plat sur une surface large où vous aurez suffisamment de place pour travailler confortablement, et enfin retirer tous les caches en plastiques des baies à lavant du PC The first stage consists in fully-opening the box, then place it on a large surface where you will have sufficient place to work comfortably, and finally to withdraw the plastic protections on the PC front side. Instruction (iterative expression), action, (goal) (argument)+, (reference), (picture)+, (warning) La première étape consiste à ouvrir entièrement le boîtier, puis de le placer à plat sur une surface large où vous aurez suffisamment de place pour travailler confortablement, et enfin retirer tous les caches en plastiques des baies à lavant du PC La premiere étape consiste à ouvrir entièrement le boîtier, puis de le placer à plat sur une surface large où vous aurez suffisamment de place pour travailler confortablement, et enfin retirer tous les caches en plastiques des baies à lavant du PC Argument Temporal marks Instructions

18 Texte title, (summary), (warning)+, (pre-requisites)+, (picture) + < objective. title Pre-requisites Objective

19 annotation Postez le formulaire et les documents au Centre de traitement des demandes. Après avoir rempli le formulaire de demande, vous devez le poster, dans lenveloppe- réponse fournie, à ladresse suivante : Centre de traitement des demandes Citoyenneté et Immigration Canada C.P. 7000 Sydney (Nouvelle-Écosse) B1P 6V6 Noubliez pas : n n de signer et de dater le formulaire ainsi que de signer vos photos; n n dinclure le reçu du paiement (formulaire IMM 5401); n n de mettre votre demande dans lenveloppe; n n de mettre les photos dans lenveloppe; n n dinclure les photocopies de tous les documents requis. Après avoir rempli le formulaire de demande, vous devez le poster, dans lenveloppe-réponse fournie, à ladresse suivante : Centre de traitement des demandes Citoyenneté et Immigration Canada C.P. 7000 Sydney (Nouvelle-Écosse) B1P 6V6 Noubliez pas : n de signer et de dater le formulaire ainsi que de signer vos photos ; n dinclure le reçu du paiement (formulaire IMM 5401) ; n de mettre votre demande dans lenveloppe ; n de mettre les photos dans lenveloppe ; n dinclure les photocopies de tous les documents requis.

20 The grammar is : -- too rigid, and not sufficient to describe all facets of procedural texts -- not very constrained -- not explicative and predictive enough A new orientation of the discursive structure of procedural texts : principles and norms Grammar limits

21 Overview Procedural questions Grammar of procedural discourse - syntactic structure - linguistic marks Questionability and responses

22 Linguistic marks (1) Discursive marks : allow for the identification of the elements of the grammar -- classical temporal marks (precedence, overlap, inclusion, etc.) -- restrictions, conditions, alternatives, comparisons, etc. -- causal marks (identification of objectives, goals, warnings, preventions, consequences, etc.)

23 -- typoraphic criterion: instruction localization (1)

24 -- morphological criterion (ex: imperatives) instruction localization (2)

25 -- semantic criterion: action verbs instruction localization (3)

26 Overview Procedural questions Grammar of procedural discourse - syntactic structure - linguistic marks Questionability and responses

27 How to download music ? Response Question analysis Procedural Question? Search engine n texts Filtering 1 Procedural texts ? Annotation Grammar Filtering 2 Unification QUESTIONABILITY

28 Questionability (1) The ability or the relevance of any text to respond to How-questions. Stage 1: determine the « CATEG » rate -- measure the procedural nature of a text Stage 2: determine the « QUEST » rate -- measure of zones which are qualified for potential question unification

29 Questionability (2) Stage 1 : « CATEG » => 3 « surface criteria » - typographic forms (TF) - morpho-syntactic marks (MSM) - articulatory marks (AM) : (temporal, argumentative, etc.) average frequency is computed for each criteria for all texts (noted as TF average, MSM average, AM average)

30 Questionability (3) For text i, we Define its CATEG rate: Selection of the « best » texts => annotation

31 Questionability (4) Stage 2 : « Quest » => evaluate the number of areas which can potentially match with How-questions 4 areas leading to 4 criteria : - number of titles (TIT) - action verbs (AV) - number of goals (GOA) - manners (MAN)

32 Questionability (5) For text i, we define its QUEST rate : Question Unification

33 Responses 3 tasks : -- selecting procedural texts which have the best questionabilty rate -- matching the question body with « questionable zones » -- extracting the relevant portion of the text and returning it to the user in a user-friendly way

34 To Conclude … Still experimental work - ongoing : design of a system that annotates texts and evaluates the questionability rate Perspectives : - validation / evaluation - unification give a complete answer to the user - respond cooperatively to procedural questions Work more specifically on the structure of legal / administrative procedural texts

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