Abstraction Elimination of Special cases Exceptions Spelling - PowerPoint PPT Presentation

Abstraction Elimination of — Special cases — Exceptions Spelling rules Punctuation Declensions Martin Kay Conjugations Cases Prepositions Stanford University and Moods The University of the Saarland … Martin Kay Translation—Symbolic Methods 1 Martin Kay Translation—Symbolic Methods 2 Morphographemic Abstraction Morphographemics walking Kind Kinder Kindern walk +ing love loves loving rubbing run runs running rub +ing manger mange mangeons try trying tries walks walk +s tie tying ties Diacritics medico medici tries try +s arco arche Spelling idiosyncracies no longer matter no longer get in the way Martin Kay Translation—Symbolic Methods 3 Martin Kay Translation—Symbolic Methods 4

Morphological Abstraction Morphological Abstraction Masc dem der Sing Dat dogs dog Plural Neut Nom schemata Männer schema Plural Mann Plur Acc Masc Gen children child Plural Acc Sing Gen Singular Dat sheep sheep Jungen Junge Masc Nom Plural Acc Plur Paradigms and exceptions no longer matter Gen Martin Kay Translation—Symbolic Methods 5 Martin Kay Translation—Symbolic Methods 6 Dat Word-level Processes Syntactic Abstraction They sent the final report to the minister Umlauting They sent the minister the final report Vowel harmony The final report, they sent to the minister To the minister they sent the final report Shortening Suffixing The final report was sent to the minister (by them) Lengthening Prefixing send Circumfixing (past) Infixing Agent Patient Ricipient Reduplication Inflexional morphology Derivational morphology pro report minister (human) Word Formation (def) (def) (plur) final Martin Kay Translation—Symbolic Methods 7 Martin Kay Translation—Symbolic Methods 8

Syntactic Abstraction Topicalization How much abstraction is enough/too much? Information structure What does it mean in English/German? John gave this perfect stranger a lot of money John gave a lot of money to this perfect stranger Broccoli, I cannot stand! One thing I cannot stand is broccoli. It is Ivan that caused all the trouble in the first place. The more broccoli there is, the less I like it. Martin Kay Translation—Symbolic Methods 9 Martin Kay Translation—Symbolic Methods 10 Other Levels Syntax? — Adjective order His clever brother always stood in his light Er stand immer im schatten seines klugen Opinion Size Age Shape Color Origin Material Purpose Bruders Fine big old wooden storage boxes He will not be here until Monday little blue Mexican model Funny round meeting room Er wird erst Montag da sein farm vegetable product Cela vous plait? How to classify organic Do you like that? recursive Hans schwimmt gern soft running Hans likes swimming/to swim … ? Martin Kay Translation—Symbolic Methods 11 Martin Kay Translation—Symbolic Methods 12

The Vauquois Triangle The Transfer Approach Semantics Abstraction Analyze to some level of abstraction L Syntax Transfer Generate Morphology Phonology Source Target Martin Kay Translation—Symbolic Methods 13 Martin Kay Translation—Symbolic Methods 14 The Vauquois Triangle Commercial Systems Do not follow the model closely: Semantics — Levels of abstraction are • Not strongly separated Syntax • Are weakly formalized at best Transfer — Generation Levels are largely eliminated Morphology Synthesis Analysis Are almost entirely deterministic Phonology Aim for speed Source Target Martin Kay Translation—Symbolic Methods 15 Martin Kay Translation—Symbolic Methods 16

The Vauquois Triangle The Standard Approach Semantics Abstraction Syntax Shallow, ad hoc Transformer Target Source parse T r Morphology a Analysis n s f e r Phonology Source Target Martin Kay Translation—Symbolic Methods 17 Martin Kay Translation—Symbolic Methods 18 Commercial Systems Commercial Systems • Weak points — Early binding — no nondeterminism — Result will, in general, be ungrammatical Rely on — Tuning the lexicon to the domain — Huge inventories of set phrases — Selectional restrictions Martin Kay Translation—Symbolic Methods 19 Martin Kay Translation—Symbolic Methods 20

The Standard Approach The Standard Approach Separate modules for simplicity, Separate modules for simplicity, maintainability, reuse maintainability, reuse Heuristic filters are applied early to avoid computational explosion Exponential Explosion � Parser Transfer Generator Parser Transfer Generator � � � Martin Kay Translation—Symbolic Methods 21 Martin Kay Translation—Symbolic Methods 22 Assessment of the Standard The Standard Approach Approach Separate modules for simplicity, maintainability, reuse • Robust Heuristic filters are applied early to avoid computational explosion • Can produce word salad • Ad hoc and hard to maintain • Bilingual and unidirectional � Parser Transfer Generator � � � Early binding Martin Kay Translation—Symbolic Methods 23 Martin Kay Translation—Symbolic Methods 24

Academic Approaches Academic Approaches Semantics • More abstraction — appeal to AI Transfer • Equal weight to analysis and generation Syntax Synthesis • Formalisation Analysis Morphology • Avoid early binding Phonology Source Target Martin Kay Translation—Symbolic Methods 25 Martin Kay Translation—Symbolic Methods 26 Academic Approaches Linguistics Problems Can identify Time Ambiguity But not resolve Robstness Ambiguity Martin Kay Translation—Symbolic Methods 27 Martin Kay Translation—Symbolic Methods 28

The Vauquois Triangle The Vauquois Triangle What is this? Semantics Semantics Syntax Syntax Morphology Morphology Phonology Phonology Martin Kay Translation—Symbolic Methods 29 Martin Kay Translation—Symbolic Methods 30 If you abstract enough Interlingua must • Represent whatever any language can represent, even if it will often be lost in translation. • Problems of (non)overlap in the semantic grid. You will be left with Pure Thought OK. So what is wrong with that? Martin Kay Translation—Symbolic Methods 31 Martin Kay Translation—Symbolic Methods 32