Upload
laureen-patterson
View
218
Download
0
Tags:
Embed Size (px)
Citation preview
January 24-25, 2003
Workshop on Markedness and the Lexicon
1
On the Priority of Markedness
Paul SmolenskyCognitive Science Department
Johns Hopkins University
January 24-25, 2003
Workshop on Markedness and the Lexicon
2
Markedness Rules
Markedness is prior to lexical frequency Developmentally
Explanatorily Markedness determines possible
inventories (e.g., of lexical items) Markedness determines relative
frequency of structuresHave few solid results; mostly suggestive
evidence, empirical and theoretical
January 24-25, 2003
Workshop on Markedness and the Lexicon
3
Developmental Priority
• Look to see whether young infants are sensitive to markedness before they’ve had sufficient relevant experience
• Before 6 months, infants have not shown sensitivity to language-particular phonotactics
January 24-25, 2003
Workshop on Markedness and the Lexicon
4
Experimental Exploration of the
Initial State
January 24-25, 2003
Workshop on Markedness and the Lexicon
5
Talk Outline
Markedness is prior to lexical frequency Developmentally
Explanatorily Markedness determines possible
inventories (e.g., of lexical items) Markedness determines relative
frequency of structures
January 24-25, 2003
Workshop on Markedness and the Lexicon
6
Markedness and Inventories
• Insert: SHarC Theorem• Insert: Lango
January 24-25, 2003
Workshop on Markedness and the Lexicon
7
Inherent Typology
• Method applicable to related African languages, where the same markedness constraints govern the inventory (Archangeli & Pulleyblank ’94), but with different interactions: different rankings and active conjunctions
• Part of a larger typology including a range of vowel harmony systems
January 24-25, 2003
Workshop on Markedness and the Lexicon
8
Summary• OT builds formal grammars directly from
markedness: MARK … with FAITH
• Inventories consistent with markedness relations are formally the result of OT … with local conjunction: TLC[Φ], SHarC theorem
• Even highly complex patterns can be explained purely with simple markedness constraints: all complexity is in constraints’ interaction through ranking and conjunction: Lango ATR harmony
January 24-25, 2003
Workshop on Markedness and the Lexicon
9
Talk Outline
Markedness is prior to lexical frequency Developmentally
Explanatorily Markedness determines possible
inventories (e.g., of lexical items) Markedness determines relative
frequency of structures [???]
January 24-25, 2003
Workshop on Markedness and the Lexicon
10
• The question is not – why does John say X more frequently than Y?, but– why does John’s speech community say X more
frequently than Y?
Markedness Frequency
• How are markedness and frequency to be theoretically related?
• Markedness theory must predict frequency distributions– Frequencies are the data to be explained
• How, within generative grammar?• Consider an extreme (but important)
distribution in cross-linguistic typology
January 24-25, 2003
Workshop on Markedness and the Lexicon
11
A Generativist Paradox• UG must not generate unattested
languages• What counts as unattested?• “The overwhelming generalization is
U; the proposed UG0 is right because all systems it generates satisfy U”
• “This UG generates the somewhat odd system X (violates U) … but this is actually a triumph because it so happens that the actual (but obscure) language L is odd like X”
Inconsistent !
celebrates: X not
generated
celebrates: X is generated
January 24-25, 2003
Workshop on Markedness and the Lexicon
12
The Generativist Paradox
• That is, how to explain generalizations of the form “Overwhelmingly across languages, U is true, but in rare cases it is violated: (an ‘exception’) X”
• Generative grammar has only two options:– Generate only U-systems: strictly prohibits X
or– Generate both U and not-U systems: allows X
• Neither explains the generalization
January 24-25, 2003
Workshop on Markedness and the Lexicon
13
The Generativist Paradox
• A proposed UG0 entails a universal U: T ≻ K
• UG0 thus predicts – if a language allows T it must also allow K – errors must be directed K T
• Suppose this is overwhelmingly true, but rarely:– a language X’s inventory includes K but not T – there are errors T K
• UG0-impossible!
– Is this evidence for or against UG0?
– Must UG0 be weakened to allow languages with K ≻ T ?
January 24-25, 2003
Workshop on Markedness and the Lexicon
14
• UG is not responsible for X; not core– Linguists’ judgment determines the core data– Good approach
Approaches to the Paradox
January 24-25, 2003
Workshop on Markedness and the Lexicon
15
• UG is not responsible for X; not core
• UG generates X and is not responsible for its rarity – Derives from extra-grammatical factors
Approaches to the Paradox
January 24-25, 2003
Workshop on Markedness and the Lexicon
16
• UG is not responsible for X; not core
• UG generates X and is not responsible for its rarity
Approaches to the Paradox
• UG generates X and derives its rarity– qualitatively or– quantitatively
I have no idea
Well, maybe three ideas …
How, within a generative theory —
OT?
January 24-25, 2003
Workshop on Markedness and the Lexicon
17
Graded Generability in OT
Idea : Ranking RestrictivenessRare systems are those produced by only a highly restricted set of rankings
• Parallel to within-language variation in OT
Grammar + Ø
January 24-25, 2003
Workshop on Markedness and the Lexicon
18
• Consider first within-language variation– a language has a range of rankings– for a given input, the probability of an
output is the combined probability of all the rankings for which it is optimal • Rankings: equal probability (Anttila) • Rankings: “Gaussian probability” (Boersma)
– works surprisingly well
Graded Generability in OT
January 24-25, 2003
Workshop on Markedness and the Lexicon
19
• Consider first within-language variation– a language has a range of rankings– for a given input, the probability of an
output is the combined probability of all the rankings for which it is optimal
Graded Generability in OT
• Can this work for cross-linguistic variation?– I haven’t a clue
• Well, maybe three clues
January 24-25, 2003
Workshop on Markedness and the Lexicon
20
Distribution of Basic Syllable Languages
CV, 47CV(C), 20
(C)V(C), 13
(C)V, 20
• Encouraging or discouraging???
Clue 1: CV Theory
January 24-25, 2003
Workshop on Markedness and the Lexicon
21
Clue 2: Constraint Sensitivity
The probabilistic interpretation would provide additional empirical constraints on OT theories:
• ¿Markedness of low-front-round (IPA Œ): ① *[+fr, +lo, +rd] or② *[+fr, +rd], *[+lo, +rd], [+fr, +lo] ?
• Faithfulness constraintsF[fr], F[rd], F[lo]
• Probability of in the inventory① 25%② 7%
Empirical probability informs constraint discovery
January 24-25, 2003
Workshop on Markedness and the Lexicon
22
Clue 3: BO(WO)nW and &D
• In Basic Inventory Theory with Local Conjunction, the proportion of rankings yielding a BO(WO)nW inventory is
1 22
(2 2 1)2 1 2~ 2
(2 2 1)!
n
n nn n
nn
en
22n
• Even when many conjunctions are present, the likelihood that they matter becomes vanishingly small as n (the order of conjunction) increases
January 24-25, 2003
Workshop on Markedness and the Lexicon
23
Graded Generability in OT
Idea . LearnabilityRarer grammars are less robustly learnable
Grammar + general learning theory
???
January 24-25, 2003
Workshop on Markedness and the Lexicon
24
Graded Generability in OT
As with Ranking Restrictiveness, start with language-internal variation
Idea Connectionist substrate Given an input I, a rare output O is one that is rarely found by the search process
Grammar + general processing theory
January 24-25, 2003
Workshop on Markedness and the Lexicon
25
Graded Generability in OT
• Problem identified by Matt Goldrick• Aphasic errors predominantly k t but
also t k occurs, rarely• Exceptional behavior w.r.t. markedness• How is this possible if *dor ≫ *cor in UG?
Under no possible ranking can t k • Must we allow violations of *dor ≫ *cor ?• Alternative approach via processing
theory• Crucial: global vs. local optimization
January 24-25, 2003
Workshop on Markedness and the Lexicon
26
OT ⇒ pr[I→O] via Connectionism
• Candidate A: realized as an activation pattern a (distributed; or local to a unit)
• Harmony of A: H(a), numerical measure of consistency between a and the connection weights W
• Grammar: W• Discrete symbolic candidate space
embedded in a continuous state space• Search: Probability of A: prT(a) ∝ eH(a)/T
– During search, T 0
January 24-25, 2003
Workshop on Markedness and the Lexicon
27
Harmony Maxima• Patterns realizing optimal symbolic
structures are global Harmony maxima• Patterns realizing suboptimal symbolic
structures are local Harmony maxima• Search should find the global optimum• Search will find a local optimum• Example: Simple local network for
doing ITBerber syllabification
January 24-25, 2003
Workshop on Markedness and the Lexicon
28
σ σ
WONSET = 28 WONSET C
a
i
r
n
z
s
d
t
Wa
Wi
Wr
Wn
Wz
Ws
Wd
Wt
C
a
i
r
n
z
s
d
t
a
i
r
n
z
s
d
t
V
8
7
6
5
4
3
2
1
W8 = 28 1
W7 = 27 1
W6 = 26 1
W5 = 25 1
W4 = 24 1
W3 = 23 1
W2 = 22 1
W1 = 21 1
V
Nuc Ons Nuc Ons
/ / t b i a
BrbrNet
January 24-25, 2003
Workshop on Markedness and the Lexicon
29
BrbrNet’s Local Harmony Maxima
An output pattern in BrbrNet is a local Harmony maximum if and only if it realizes a sequence of legal Berber syllables (i.e., an output of Gen)
That is, every activation value is 0 or 1, and the sequence of values is that realizing a sequence of substrings taken from the inventory {CV, CVC, #V, #VC},
where C denotes 0, V denotes 1 and # denotes a word edge
January 24-25, 2003
Workshop on Markedness and the Lexicon
30
Competence, Performance• So how can t k ?
– t a global max, k a local max– now we can get k when should get t
• Distinguish Search Dynamics (‘performance’) from Harmony Landscape (‘competence’)– the universals in the Harmony Landscape require
that, absent performance errors, we must have k t
– an imperfect Search Dynamics allows t k
• The huge ‘general case/exception’ contrast– t’s output derives from UG– k’s output derives from performance error
January 24-25, 2003
Workshop on Markedness and the Lexicon
31
Summary• Exceptions to markedness universals may
potentially be modeled as performance errors: the unmarked (optimal) elements are global Harmony maxima, but local search can end up with marked elements which are local maxima
• Applicable potentially to sporadic, unsystematic exceptions in I O mapping
• Extensible to systematic exceptions in I O or to exceptional grammars???
January 24-25, 2003
Workshop on Markedness and the Lexicon
32
Markedness Rules
Markedness is prior to lexical frequency Developmentally
Explanatorily Markedness determines possible
inventories (with local conjunction) Markedness determines relative
frequency of structures --- ???