11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 1 E mbedding Implicatures: global or local? Reinhard Blutner department of philosophy.

Slides:



Advertisements
Similar presentations
1 Knowledge Representation Introduction KR and Logic.
Advertisements

Kees van Deemter Matthew Stone Formal Issues in Natural Language Generation Lecture 4 Shieber 1993; van Deemter 2002.
Optimality Theory Lexical Semantics Tandem workshop on Optimality Theory in language and geometric approaches to language.
Semantics (Representing Meaning)
Kaplan’s Theory of Indexicals
Inference and Reasoning. Basic Idea Given a set of statements, does a new statement logically follow from this. For example If an animal has wings and.
CAS LX 502 Semantics 10b. Presuppositions, take
Presuppositions (and Focus) Sabine Iatridou. What does it mean to understand (the meaning of) a sentence? Do you understand this sentence? 1.The instructor.
The Cooperative Principle
Knowledge Representation
Presupposition General definition: entailment under negation. I don’t regret saying it. I regret saying it. A topic of much interest in philosophy: the.
Introduction: The Chomskian Perspective on Language Study.
Linguistic Theory Lecture 7 About Nothing. Nothing in grammar Language often contains irregular paradigms where one or more expected forms are absent.
On Status and Form of the Relevance Principle Anton Benz, ZAS Berlin Centre for General Linguistics, Typology and Universals Research.
Lecture 11: Binding and Reflexivity.  Pronouns differ from nouns in that their reference is determined in context  The reference of the word dog is.
11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 1 E mbedding Implicatures: global or local? Reinhard Blutner LeGO jaargang 10 aflevering.
Discourse Martin Hassel KTH NADA Royal Institute of Technology Stockholm
Albert Gatt LIN1180 – Semantics Lecture 10. Part 1 (from last week) Theories of presupposition: the semantics- pragmatics interface.
Online processing of bidirectional optimization Petra Hendriks, Jacolien van Rij & Hedderik van Rijn Tandem Workshop on Optimality in Language and Geometric.
Linguistic Theory Lecture 8 Meaning and Grammar. A brief history In classical and traditional grammar not much distinction was made between grammar and.
OT learning and the development of coreference Reinhard Blutner University of Amsterdam Anton Benz Syddansk University Kolding 2005.
Week 5a. Binding theory CAS LX 522 Syntax I. Structural ambiguity John said that Bill slipped in the kitchen. John said that Bill slipped in the kitchen.
CAS LX 502 Semantics 1b. The Truth Ch. 1.
Implicatures Henriëtte de Swart. Background and modern views on conversational implicatures Simons (2008) ~ Gricean view (background) Chierchia et al.
Universiteit van amsterdam | 1 Reinhard Blutner How realistic is bidirectional optimization? Institute for Logic,
PSY 369: Psycholinguistics Some basic linguistic theory part3.
Week 14b. PRO and control CAS LX 522 Syntax I. It is likely… This satisfies the EPP in both clauses. The main clause has Mary in SpecIP. The embedded.
Meaning and Language Part 1.
Lecture 1 Introduction: Linguistic Theory and Theories
February 2009Introduction to Semantics1 Logic, Representation and Inference Introduction to Semantics What is semantics for? Role of FOL Montague Approach.
Pragmatics.
Game Theory and Grice’ Theory of Implicatures Anton Benz.
11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 1 E mbedded Implicatures, Fossilization, and Incremental Interpretation Reinhard Blutner.
Binding Theory Describing Relationships between Nouns.
1 B idirectional optimization from the perspective of experimental pragmatics Reinhard Blutner Universiteit van Amsterdam June 11, 2007 ∙ ZAS Berlin.
Advanced Topics in Propositional Logic Chapter 17 Language, Proof and Logic.
Universiteit van amsterdam December 14-16, 2007 | 1 Reinhard Blutner Optimality-Theoretic Pragmatics Meets Experimental.
ARTIFICIAL INTELLIGENCE [INTELLIGENT AGENTS PARADIGM] Professor Janis Grundspenkis Riga Technical University Faculty of Computer Science and Information.
LOGIC AND ONTOLOGY Both logic and ontology are important areas of philosophy covering large, diverse, and active research projects. These two areas overlap.
1 LIN 1310B Introduction to Linguistics Prof: Nikolay Slavkov TA: Qinghua Tang CLASS 24, April 3, 2007.
Presupposition and Entailment James Pustejovsky September 23, 2005.
Levels of Language 6 Levels of Language. Levels of Language Aspect of language are often referred to as 'language levels'. To look carefully at language.
Meaning. Deictics  Are words, phrases and features of grammar that have to be interpreted in relation to the situation in which they are uttered such.
LECTURE 2: SEMANTICS IN LINGUISTICS
Presupposition is what the speaker assumes to be the case prior to making an utterance. Entailment, which is not a pragmatic concept, is what logically.
Scalar implicatures and adjectives Can a decent student get into Harvard? A study on gradable adjectives and scalar implicatures XPRAG2011 Barcelona Some.
Presentation about pragmatic concepts Implicatures Presuppositions
Michelle C. Delos Reyes. meaning of a word = concept It may appear as a constituent of a logical form. It appears as an.
Welcome Back, Folks! We’re travelling to a littele bit far-end of Language in Use Studies EAA remains your faithful companion.
UNIT 2 - IMPLICATURE.
Topic and the Representation of Discourse Content
ADRESS FORMS AND POLITENESS Second person- used when the subject of the verb in a sentence is the same as the individual to.
Optimal answers and their implicatures A game-theoretic approach Anton Benz April 18 th, 2006.
Lecture 1 Ling 442.
Competing Conceptions of Language Dr. Douglas Fleming University of Ottawa.
Pragmatics. Definitions of pragmatics Pragmatics is a branch of general linguistics like other branches that include: Phonetics, Phonology, Morphology,
Why languages differ: Variation in the conventionalization of constraints on inference By: Randy J. LaPolla City University of Hong Kong Presented by:
5 Lecture in math Predicates Induction Combinatorics.
Implicature. I. Definition The term “Implicature” accounts for what a speaker can imply, suggest or mean, as distinct from what the speaker literally.
PRESUPPOSITION AND ENTAILMENT
COMMUNICATION OF MEANING
2nd Language Learning Chapter 2 Lecture 4.
COOPERATIVE PRINCIPLE:
Language, Logic, and Meaning
The Cooperative Principle
How to Avoid Redundant Object-References
The Cooperative Principle
RELEVANCE THEORY Group Members Sana saif Huma Wazir Junaid Ahmed
ALI JABBER KARAM Presented by :
Presupposition and Entailment
Presentation transcript:

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 1 E mbedding Implicatures: global or local? Reinhard Blutner department of philosophy UvA 2006

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 2 Local and global theories of NL interpretation  Local Theories –The (grammatical) status of a (linguistic) expression S is decided exclusively considering properties of S, and the properties of other linguistic objects S' are completely irrelevant for this decision. –The interpretation of S is independent of the existence of related linguistic expressions S' that share the interpretation  Global Theories (competition-based) –There are different linguistic expressions in competition. The winner of the competition suppresses the other competing candidates, ruling them out from the set of well- formed linguistic objects –Interpretations of S can be blocked by the existence of competitive forms S'.

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 3 Examples LocalGlobal Syntax Traditional generative syntax OT syntax connectionism Semantics Montague semantics Interpretive optimi- zation (Hendriks & de Hoop) Early structuralism & lexical field theories Bidirectional optimi- zation Presuppos. Van der Sandt, GeurtsZeevat (discourse particles) Implicature Relevance Theory Chierchia 2004 Neo-Gricean theories OT-Pragmatics

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 4 Questions  Is there only one truth: Either local or global?  If local and global theories can coexist: What is their proper place?  What is the relation between both theories? How to transform global theories into local ones?

1 Embedded implicatures  Explicature and implicature  Embedded implicature hypothesis (EIH)  R-based implicatures generally satisfy EIH  Q-based implicatures can violate EIH

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 6 The relevance theoretic distinction between explicature and implicature  Explicatures are assumptions constructed by developing the logical forms encoded by the utterance. Implicatures are assumptions constructed by “developing assumption schemes retrieved from encyclopaedic memory” (Sperber & Wilson 1986, p. 181)  An Explicature is a pragmatically determined part of what is said (‘truth-conditional pragmatics’). Implicatures proper relate to the non-truth-conditional aspects of pragmatics (Carston 2002)  E: John had a drink ⇝ John had an alcoholic drink I: Some students wrote an essay ⇝ not all students wrote an essay

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 7 Embedding and Scope  Scope principle: A pragmatically determined aspect of meaning is part of what is said (and therefore, not a conversational implicature), if – and perhaps only if – it falls within the scope of logical operators such as negation and conditionals. (Carston 2002: 191)  Obviously, this principle is related to Green’s ‘Embedded Implicature Hypothesis’ (EIH): EIH: If assertion of a sentence S conveys the implicatum that p with nearly universal regularity, then when S is embedded the content that is usually understood to be embedded for semantic purposes is the proposition S&p. (Green, 1998: 77)

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 8 Embedded implicature hypothesis (EIH) ( 1')a. I believe that John had a drink ⇝ I believe that John had an AD b. I doubt that John had a drink ⇝ I doubt that John had an AD (2')a. I believe that some students wait for me ⇝ I believe that some but not all students wait for me b. I doubt that some students wait for me ⇝ I believe that no students wait for me c. I doubt that some students wait for me ⇝ I doubt that some but not all students wait for me [too weak!] d. ?Possibly all students are waiting for me. Hence, I doubt that some students are waiting for me. EIH seems to hold for R-based implicatures (  explicatures) but not generally for Q-based implicatures /

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 9 R-based implicatures satisfy EIH (3)a. I lost a contact lens in the accident ( ⇝ contact lens of the Speaker) b. I didn’t lose a contact lens in the accident, but Mary did c. Either Mary lost a contact lens in the accident or Bob did (4)a. Peter drank several beers and drove home ( ⇝ temporal sequence) b. If Peter drank several beers and drove home, then I will really be disappointed b. If Peter drove home and drank several beers, then I will not be disappointed The intuitive truth-conditional content of an utterance may go well beyond the proposition obtained by decoding, disambiguation and reference assignment. The following examples illustrate free enrichment as a pragmatic processes that contribute to the recovery of the proposition expressed by an utterance. Neo-Griceans would classify them as R-based

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 10 More R-based implicatures Domain restrictions (5)a. Everyone left early ( ⇝ everyone at the party left early) b. Either everyone left early or the ones who stayed on are in the garden Meronomic restriction (6)a. This apple is red ( ⇝ the outside of the apple is red) b. I doubt that this apple is red Reciprocals and plural predication (7)a. The girls saw each other ( ⇝ every girl saw every other girl) b. I doubt that the girls saw each other. No girl sees girl 5 (8)a. The cats see the dogs ( ⇝ every cat sees every dog) b. I doubt that the cats see the dogs. No cat sees dog 3 (9)a. The cats are sitting in the baskets ( ⇝ every cat is sitting in one of the baskets) b. # I doubt that the cats are sitting in the baskets. No cat is sitting in basket 3, all cats are sitting in baskets 1 and 2 (Winter 2001)

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 11 Q-based implicatures violate EIH (10)a. Mary lives somewhere in the south of France b. Speaker does not know where in the south of France Mary resides. c. If Mary lives somewhere in the south of France, then I do not know where d. If (c) would satisfy EIH, then it should be a tautology, see Carstons p. 194) (11)a.  ⇝ ¬K , with  stronger than  b.  x  (x) ⇝ ¬K  (a), for each individual place a c.  x  (x)  ¬K  (a) [no stronger alternatives] d. (  x  (x) & ¬K  (a))  ¬K  (a) [tautology for local solution].

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 12 Scalar implicatures: or (12)a. If Paul or Bill come, Mary will be upset b. #But if Paul and Bill both come, Mary won’t be c. If Paul comes, Mary or Sue will be upset The local implicature (EIH) is not realized in the antecedent but in the conclusion (13)I wasn’t shocked because I touched the red wire OR the blue wire. I was shocked because I touched both. (D. Fox) The local implicature IS realized in the antecedent when the OR is marked (14)John doubts that Paul or Bill are in that room. (This sentence cannot be used if it is evident for John that both are in the room) The local implicature is not realized in negative embedding predicates (15)Did John or Paul arrive? a. # No; they both did b. Yes, they both did In questions, the local implicature does not appear

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 13 Scalar implicatures: count nouns (16)a. John: “My colleague makes $ 100 an hour” b. John believes that his colleague makes $ 100 an hour c. If he makes $ 100 an hour then he must be very rich. Again the local implicature is realized in (b) but not in (c) (17)a. If John has two cars, the third one parked outside must be somebody else’s. b. If John has two cars and no more, the third one parked outside must be somebody else’s Chierchia (p.24) describes this as an accommodation (what is different from a local implicature)  Conclusion: The scalar implicatures connected with count nouns only appear in upward entailing contexts.

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 14 Conclusions of the empirical part  R-based implicatures are Explicatures (satisfying EIH)  Q-based implicatures do not generally satisfy EIH (roughly: they locally project in upward entailing contexts but not in downward entailing contexts)  Apparent counterexamples do not destroy this picture: –I wasn’t shocked because I touched the red wire OR the blue wire. I was shocked because I touched both. –Usually you may only take an apple. So, if you may take an apple OR take a pear, you should bloody well be pleased.

2 Global theories  Neo-Gricean theories are global  Can a global theory explain EIs? - Q-based (Sauerland and others) - R-based (notion of Relevance)

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 16 Conversational Implicatures I-principle (termed R by Horn)Q-principle Quantity 2, Relation  Say no more than you must (Horn 1984)  Read as much into an utterance as is consistent with what you know about the world [Levinson 1983: 146f.] Quantity 1  Say as much as you can (Horn 1984).  Do not provide a statement that is informationally weaker than your knowledge of the world allows, [Levinson 1987: 401] Conditional perfection, neg-raising, bridging  Seeks to select the most harmonic interpretation Interpretive Optimization Scalar implicatures  Can be considered as a blocking mechanism Expressive Optimization (given Q) (given I) (bearing the Q-principle in mind). unless providing a stronger statement would contravene the I-principle

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 17 Can a global theory explain EIs?  I think it can explain the contrast between explicatures and implicatures proper, with three provisos: –reconsideration of the epistemic status of Q-based implicatures:  ⇝ ¬K  rather than  ⇝ K¬  –possibility of strengthening: ¬K  ⇝ K¬  –proper definition of relevance for R-based implicatures  R-based implicatures satisfy EIH  Q-based implicatures project in a different way (roughly: they locally project in upward entailing contexts but not in downward entailing contexts)

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 18 In defense of a global theory (Q)  Only a global theory can explain  (  A)B ⇝ (  A)B [because the blocking clause  K  (  A)B results in an embedding implicature K((  A)B)]  A global theory accounts for the implicatures due to embedded scalar implicatures, e.g. K(  A)B ⇝ K(  A)  B [because the blocking clause  K(  A)B is strengthened to K  (  A)B, i.e. K(  A)  B]  In downward entailing context no blocking term is available for some. Hence, the EIH is violated.

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 19 In defense of a global theory (R)  For the proper treatment of R-based implicatures we need a proper measure of relevance –BE Strong (maximize informativity) fails for negative contexts –The same for the relevance-theoretic notion of relevance (maximize the contextual effect) –However, there are appropriate measures of the relevance of complex sentences.

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 20 Relevance (Merin 1997) Three conditions of a local theory of relevance (1) Rel(A&B) = Rel(A)+Rel(B) if A and B are independent (2) Rel(A) = -Rel(  A) (3) Rel(A  B) =  Rel(A) +(1-  )Rel(  A) with 0    1

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 21 Relevance (following van Rooy 2004)  Goal-directed relevance functions –Standard statistical relevance: r(G, A) = P(G/A) – P(G) –Carnap’s relevance: c(G, A) = P(G  A) – P(G)  P(A) –Good’s relevance: g(G, A) = log P(A/G) – log P(A/  G)  Other notions –Merin, reconstructing RT’s contextual effect CE(A,C) = inf(A|C), with inf(A|C) = -log2 prob(A|C) –Van Rooy: Relevance of an answer to a question  Q (A) = E(Q) - E(Q|A)

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 22 Optimal enrichments of underspecified logical forms LF  Fact: If m is an optimal enrichment of LF then  m is an optimal enrichment of  LF  Proof: –Assume a local enrichment mechanism for logical forms, i.e. m is an enrichment of LF   m is an enrichment of  LF –Assume Rel(m) = -Rel(  m) –Consequently, m is an optimal enrichment of LF   m is an optimal enrichment of  LF  It can be concluded that EIH is inherited by negation, i.e. if a structure S satisfies EIH, then also  S satisfies it.

3 Local theories  Local projection mechanism  In defense of a local theory  Blocking cannot be an online phenomenon

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 24 Local projection mechanism  Local theories use a compositional mechanism in order to calculate the implicatures of complex sentences. –Basic implicatures are connected to particular lexical items –They project in an obvious way in case EIH is satisfied –If EIH is not generally satisfied a more refined projection mechanism is required (e.g. Chierchia’s)

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 25 In defense of a local theory  Only local theories can account for an incremental interpretation mechanism.  Experimental pragmatics has stressed the automaticity of processing conversational implicatures (Tanenhaus, Noveck, Breheny, etc.). The emergence of local theories conforms to automatization.

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 26 Blocking cannot be an online phenomenon  A problem for Neo-Gricean theories: There is no direct way to analyse blocking as an online, incremental mechanism  This holds both for simple and complex sentences  Therefore, the blocking of certain interpretations has to be treated as an offline phenomenon. For instance, it can be seen as a consequence of (bidirectional) learning  Hence, the effect of blocking is a fossilization phenomenon

4 Global and local theories as two different perspectives  Different time scales  Toward a unified theory: Fossilization  Example 1: some and all  Example 2: Pronouns and reflexives

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 28 Different time scales  A global theory such as bidirectional OT pragmatics should be seen as describing diachronic forces that explains conversational implicatures as the product of rational behaviour between cooperative conversants on a diachronic time scale  This does not conflict with local theories (Chierchia 2001, …) which take a synchronic perspective and assume that scalar implicatures are computed automatically in the grammar by means of special semantic composition rules.

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 29 Towards a unified theory: Fossilization  The idea of Fossilization provides an explanation of how local theories of interpretation emerge from global ones  In the framework of OT, local theories of interpretation conform to unidirectional, interpretive optimization  Global theories of interpretation conform to bidirectional optimization  Hence, the mechanism of fossilization can be understood as a transformation that turns a bidirectional OT system into a (nearly equivalent) unidirectional one. The latter conforms with incremental interpretation whereas the former does not.

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 30 Some roots of the idea  ‘Invited Inferences’ (Geis & Zwicky 1971). Mechanism of conventionalization for implicatures  Traugott (2005 and earlier) applied the idea to explain language change (lexicalization and language change)  Levinson (2000) und Mattausch (2004) used the idea for explaining the development of binding principles.

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 31 Applications  Deriving a local theory of embedded implicatures from a global (neo-Gricean) theory  Fossilization of simple scalar implicatures  The idea of fossilization as a starting point for resolving puzzles in experimental pragmatics –Some elephants have a trunck: why children sometimes think more logical than adults (Noveck) –The acquisition of binding principles: why children sometimes misinterpret pronouns while correctly producing them (Hendriks & Spenader) Too difficult at the moment

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 32 Example 1: Some and all  Experimental Pragmatics: Noveck u.a. –Some elephants live in the zoo (appropriate) yes 90% 99% –All elephants live in the zoo (inappropriate)no 99% 99% –Some elephants have trunks (inappropriate) yes 85% 41% –All elephants have trunks (appropriate) yes 99% 96% –Some elephants have wings (absurd)no 99% 98% –All elephants have wings (absurd)no 99% 99%  Why children sometimes think more logical than adults?  Two possible answers –metalinguistic ability for perspective changing (bidirektional reasoning) not yet developed –Fossilization not yet progressed Adults 10-11

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 33 Two possible answers FunctionalFormal Genetic evolution Evolutionary Psychology (Pinker) Minimalist program (Chomsky) Cultural evolution Recruitment theory (Steels) Iterated learning (Kirby, Hurford, Zuidema)  Metalinguistic abilities for perspective changing (bidirektional reasoning) not yet developed  Fossilization not yet proceeded

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 34 The implementation of the first answer  Lexical Constraint A: all  Set-inclusion  Referential Economy: prefers all >> some  Bidirectional Solutions some all some all

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 35 The implementation of the second answer: (Iterated) Learning m f m’ SpeakerHearer m = m’ ? If yes, nothing happens If no, adjustment: All constraints that favour (f, m) over (f, m’) are promoted All constraints that favour (f, m’) over (f, m) are demoted

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 36 The second answer: Fossilization  Lexical Constraint A: all  Set-inclusion  Referential Economy: all >> some  Potential lexical Constraint B: some  Set-intersection; …. some all some all Speaker all Hearer nothing happens Constraint B strengthened Speaker some Hearer nothing happens

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 37 Can we empirically distinguish between the two possible answers?  Look for similar examples of blocking within other lexical domains  According to the solution of evolutionary psychology the crucial developmental stages should appear synchronously for the different domains  According to the solution of (iterated) learning the time course of the development is not necessarily synchronized but may crucially depends on factors of frequency and other use factors.

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 38 Children’s interpretation and production of pronouns and reflexives (1)Bert saw himself (2)Bert saw him  Sentences like (1) are correctly understood from the age of 3;0  The him in (2) is misinterpreted as coreferring with the subject about half the time. Children continue to perform poorly on the interpretation of pronouns even up to the age of 6;6.  Production: Even very young children (ranging from 2;3 to 3;10), consistently used the pronoun to express a disjoint meaning while they used the reflexive to express a coreferential interpretation (more than 95% correct)

11/28-29/2005 NWO/DFG workshop Modelling incremental interpretation. 39 Comparing two cases of blocking pro self disjconj pro self disj conj some all some all 7 years old 12 years old

5 Conclusions  Local and global approaches can coexist. Local approaches conform to a synchronic view, global approaches conform to a diachronic view.  Hence, we can see the synchronic account as informed by a diachronic account. Conforms to the classical view of ‘Grammaticalization’ = the harnessing of pragmatics by a grammar (Haiman 1985)  In OT, the mechanism of fossilization can be understood as a transformation that turns a bidirectional OT system into a (nearly equivalent) unidirectional one. The latter conforms with incremental interpretation whereas the former does not.