2022
pdf
bib
abs
LinearTime Calculation of the Expected Sum of Edge Lengths in Random Projective Linearizations of Trees
Lluís AlemanyPuig

Ramon FerreriCancho
Computational Linguistics, Volume 48, Issue 3  September 2022
The syntactic structure of a sentence is often represented using syntactic dependency trees. The sum of the distances between syntactically related words has been in the limelight for the past decades. Research on dependency distances led to the formulation of the principle of dependency distance minimization whereby words in sentences are ordered so as to minimize that sum. Numerous random baselines have been defined to carry out related quantitative studies on lan guages. The simplest random baseline is the expected value of the sum in unconstrained random permutations of the words in the sentence, namely, when all the shufflings of the words of a sentence are allowed and equally likely. Here we focus on a popular baseline: random projective per mutations of the words of the sentence, that is, permutations where the syntactic dependency structure is projective, a formal constraint that sentences satisfy often in languages. Thus far, the expectation of the sum of dependency distances in random projective shufflings of a sentence has been estimated approximately with a Monte Carlo procedure whose cost is of the order of Rn, where n is the number of words of the sentence and R is the number of samples; it is well known that the larger R is, the lower the error of the estimation but the larger the time cost. Here we pre sent formulae to compute that expectation without error in time of the order of n. Furthermore, we show that star trees maximize it, and provide an algorithm to retrieve the trees that minimize it.
2021
pdf
bib
The Linear Arrangement Library. A new tool for research on syntactic dependency structures.
Lluís AlemanyPuig

Juan Luis Esteban

Ramon FerreriCancho
Proceedings of the Second Workshop on Quantitative Syntax (Quasy, SyntaxFest 2021)
pdf
bib
Dependency distance minimization predicts compression
Ramon FerreriCancho

Carlos GómezRodríguez
Proceedings of the Second Workshop on Quantitative Syntax (Quasy, SyntaxFest 2021)
2019
pdf
bib
Proceedings of the First Workshop on Quantitative Syntax (Quasy, SyntaxFest 2019)
Xinying Chen

Ramon FerreriCancho
Proceedings of the First Workshop on Quantitative Syntax (Quasy, SyntaxFest 2019)
pdf
bib
SyntaxFest 2019 Invited talk  Dependency distance minimization: facts, theory and predictions
Ramon FerreriCancho
Proceedings of the First Workshop on Quantitative Syntax (Quasy, SyntaxFest 2019)
2007
pdf
bib
Correlations in the Organization of LargeScale Syntactic Dependency Networks
Ramon Ferrer i Cancho

Alexander Mehler

Olga Pustylnikov

Albert DíazGuilera
Proceedings of the Second Workshop on TextGraphs: GraphBased Algorithms for Natural Language Processing