Why are some word orders more common than others In the majority of languages with dominant word order subjects precede objects SOVSVO gt VSO gt VOS OVS gt OSV Genetically encoded bias ID: 294982
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Slide1
Information Density and Word OrderSlide2
Why are some word orders more common than others?
In the majority of languages (with dominant word order) subjects precede objects
(SOV,SVO) > VSO > (VOS, OVS) > OSVSlide3
Genetically encoded bias?
Single common ancestor (SOV)?
General linguistic principles
Theme-first Verb-object bodningAnimate-firstGreat, but why do these principles work?
Why are some word orders more common than others?Slide4
Constant information transmission rate
Slower for unexpected, high entropy content
Faster for predictable, low entropy content
The basic word order of a language influences the average transmission rateThus languages that are closer to the UID ideal will be more common compared to others further away from itUniform information density hypothesisSlide5
Word-order model
Simple world with
13 objects (O)
5 people8 food/drink items 2 relations (R) eat/drinkEvents in this world consist of one relation and two objects(o
1
, r, o
2
)
And appear with a certain probability
PSlide6
Base entropy (the initial state of the observer before words are spoken)
After each word, observers adjust their expectations for the following ones, reaching an entropy of zero after the third word of the event
Word-order modelSlide7
Each event has an information profile
I
1
= H0 − H1 , I2 = H2 − H1 , I
3
= H
2
Where
H
n
are entropy trajectories of each word
UID suggests a straight line from base entropy to zero entropy such that each word conveys 1/3 of the total information
Word-order modelSlide8Slide9
Word-order model
UID deviation score
Deviation of toy-world events from the “ideal information profile” according to UID
VSO > VOS > SVO > OVS > SOV > OSVSlide10
Corpus study
Child-directed speech (English and Japanese corpora)
Utterances involving singly transitive verbs
Ignored adjectives, plurality, tense etcEnglish: VSO (0.38), SVO (0.41), VOS (0.48), SOV (0.64), OSV (0.78), OVS (0.79) Japanese: SVO (0.66), VSO (0.71), SOV (0.72), VOS (0.72), OSV (0.82), OVS (0.83) Slide11Slide12
Experiment
Languages must be optimal with respect to the frequencies of events in the real world
Judgement
tasks for pairs of sentences (which one is more probable?)VSO (0.17), SVO (0.18), VOS (0.20), SOV (0.23), OVS (0.23), OVS (0.24). Slide13
Discussion
Object-first word orders are rare
Object-first word orders have least uniform information density
(first word carries too much information)SOV is not as compatible with the UID as it is frequent in real languages – perhaps due to other important factors beside UIDTFP and AFP favor SOV, SVO (highest ranked in the results) and VSO – perhaps UID provides some justification at least for some word order rankingsSlide14
Conclusion
Findings consistent with a
weaker
hypothesis that word order is optimal wrt the frequency speakers choose to discuss events (not wrt to how often these events really occur)UID may not provide explanation for all of the word order rankings, but does explain several aspects of the empirical distribution of word ordersSlide15
A Noisy Channel Account of
Crosslinguistic
Word Order Variation
In 96.3% of studied languages S precede OSVO (English) and SOV (Japanese) are more prevalent than VSOPeople construct sentences from and agent perspective – why SVO/SOV then?Innate universal grammar – independent of communicative or performance factorsSlide16
Why SOV/SVO
Communicative-based explanation
SOV default for the human language
Preference for S to precede OPreference for the V to appear in the end of the clauseSVO arises from SOV as a result of communication/memory pressures that sometimes outweigh the second preferenceSlide17
Shanon’s
communication theory
Comprehension and production operate via a noisy channel
Speakers are under constraints to chose utterances that will ensure maximal meaning recoverability by the listenerWhen does word order affect how easily meaning can be recovered?The girl kicks the ball. (people should adhere to SOV)
The girl kicks the boy.
(potential confusion resolved perhaps by the position of the noun
wrt
to the verb)Slide18
Method
Study
investigates whether gestured word order across languages (English-SVO, Japanese, Korean-SOV) is depending on semantic reversibility of the event
Initial bias to SOVInitial bias to native language Communicative or memory pressuresEnglish Shift to SVO (second and third factors)Japanese&Korean
Shift to SVO (only due to the third factor)Slide19
Method
Brief silent animations of intransitive/transitive events
First verbally described the animations
Then hand-gestured the meanings of the events Verbal and gesture responses were coded for the relative position of the agent, action, and patientSlide20Slide21
Experiment 1
Animate/inanimate patients (reversible or non-reversible sentences)
More SVO word orders should be produced if reversible
Results – uniformly SVO for verbal responsesGestured S before O for animate patientsGestured V before O for human patients (as expected)Overwhelmingly gestured SOV for non-reversible eventsSlide22Slide23
Experiment 1&2 – Japanese/Korean
English participants’ results can be explained without resorting to noisy-channel hypothesis
Participants may shift from SOV to native (SVO) due to increased ambiguity in reversible events
Thus, tested participants with a SOV native languageExpected shift to SVO in reversible eventsExperiment 2 – used more complex structuresThe old woman says that the fireman kicks the girlSlide24Slide25
If participants use native word-order (SOV)
Then they should gesture both levels of embedded events with the same order:
S1 [S2O2V2] V1
In case of reversible events SOV creates maximal potential confusion
Then they should gesture using SVO:
S
1
V
1
[S
2
V
2
O
2
]
Experiment 1&2 – Japanese/KoreanSlide26Slide27
Exp
1 results – native language word-order
J&K speakers verbalized patient before action (100%)
Gestured patient before action in both animate and inanimate patientsExp 2 results – shift to SVOJ speakers never verbalized SVO; K speakers rarely Both J&K speakers almost always gestured top-level verb in 2
nd
position between the top-level subject and the embedded subject
In the embedded clause patients were gestured before the action almost always, but more often in non-reversible events (both for J&K speakers)
Results predicted by noisy-channel but not by the combination of SOV default and native-language order
Experiment 1&2 – Japanese/KoreanSlide28
Experiment 3
Alternative explanation of previous results
Minimizing syntactic dependency distances
Number of words between a syntactic head (verb) and its dependents (subject and object)Shorter dependencies are easierShift from SOV to SVO given that SVO allows for shorter dependency distancesSlide29
Experiment 3 - method
Animations of a boy and a girl interacting with one of a set of objects:
Circle/star/heart which was either
Spotted/striped (surface); in a box/pail (container); wearing a top/witch’s hat (headwear)Giving/putting/intransitive eventParticipants were to gesture each event and the features of the object
If sensitive to distance b/n agent and verb, then higher SVO gesture order for longer patient descriptions
No such shift predicted by noisy channel – patient is not a possible agent of the verb, adding modifiers will not affect the recoverability of who is doing what to whomSlide30Slide31
Gestured patient before action for most of events
Verbalized action before patient for most of events
Even with long productions still gestured patient before action, consistently with the noisy-channel hypothesis and not with the dependency-distance hypothesis
Experiment 3 - resultsSlide32
Discussion
English speakers have a strong SOV preference for non-reversible events even when the inanimate patient has up to 3 features to be gestured
SOV seems to be the preferred word order in human communication
For reversible events the preference for SOV disappears in favor of SVOAlthough SOV-natives gesture SOV in simple events, they revert to SVO for more complex onesThis shift to SVO occurs in order to maximize meaning recoverabilitySlide33
Discussion
Case marking is often used in SOV
Mitigates the confusability of subject and object, helping to retain the default SOV
If no case marking is used, then SVO shiftLarge majority of SOV languages are case marked, whereas few of SVO areUsed
location in space
as possible case marking
in the experiments
Of the case-marked gestures most had SOV order
Animacy
-dependent case marking
Many languages mark only animate direct objects
Non SVO languages have more word-order flexibility than SVO
Contain other mechanisms for disambiguation
So fixed word orders mostly SVOSlide34Slide35
Conclusion
No need for sophisticated innate machinery to explain word-order variation
Many aspects of
crosslinguistic word-order variance are easily explained by communicative or memory pressures