Information Theoretic Causal Inference Of Lexical Flow

This volume seeks to infer large phylogenetic networks from phonetically encoded lexical data and contribute in this way to the historical study of language varieties. The technical step that enables progress in this case is the use of causal inference algorithms. Sample sets of words from language varieties are preprocessed into automatically inferred cognate sets, and then modeled as information-theoretic variables based on an intuitive measure of cognate overlap. Causal inference is then applied to these variables in order to determine the existence and direction of influence among the varieties. The directed arcs in the resulting graph structures can be interpreted as reflecting the existence and directionality of lexical flow, a unified model which subsumes inheritance and borrowing as the two main ways of transmission that shape the basic lexicon of languages. A flow-based separation criterion and domain-specific directionality detection criteria are developed to make existing causal inference algorithms more robust against imperfect cognacy data, giving rise to two new algorithms. The Phylogenetic Lexical Flow Inference (PLFI) algorithm requires lexical features of proto-languages to be reconstructed in advance, but yields fully general phylogenetic networks, whereas the more complex Contact Lexical Flow Inference (CLFI) algorithm treats proto-languages as hidden common causes, and only returns hypotheses of historical contact situations between attested languages. The algorithms are evaluated both against a large lexical database of Northern Eurasia spanning many language families, and against simulated data generated by a new model of language contact that builds on the opening and closing of directional contact channels as primary evolutionary events. The algorithms are found to infer the existence of contacts very reliably, whereas the inference of directionality remains difficult. This currently limits the new algorithms to a role as exploratory tools for quickly detecting salient patterns in large lexical datasets, but it should soon be possible for the framework to be enhanced e.g. by confidence values for each directionality decision.

This volume seeks to infer large phylogenetic networks from phonetically encoded lexical data and contribute in this way to the historical study of language varieties. The technical step that enables progress in this case is the use of causal inference algorithms. Sample sets of words from language varieties are preprocessed into automatically inferred cognate sets, and then modeled as information-theoretic variables based on an intuitive measure of cognate overlap. Causal inference is then applied to these variables in order to determine the existence and direction of influence among the varieties. The directed arcs in the resulting graph structures can be interpreted as reflecting the existence and directionality of lexical flow, a unified model which subsumes inheritance and borrowing as the two main ways of transmission that shape the basic lexicon of languages. This work was published by Saint Philip Street Press pursuant to a Creative Commons license permitting commercial use. All rights not granted by the work's license are retained by the author or authors.

Variation Rolls the Dice: A worldwide collage in honour of Salikoko S. Mufwene aims to celebrate Mufwene’s ground-breaking contribution to linguistics in the past four decades. The title also encapsulates his approach to language as both systemic and socio-cultural practices, and the role of variation in determining particular evolutionary trajectories in specific linguistic ecologies. The book therefore focuses on variation within and across languages, within and across speakers, and how this fundamental aspect of human behavior can affect language structure in time and space. Mufwene has been instrumental in putting creole languages on the map of General Linguistics and connecting their analysis to issues of language acquisition, multilingualism, language contact, language evolution, and language typology. Thanks to the diversity of topics and the wide-ranging theoretical persuasions of the contributors, this volume aims at a large readership including both scholars and advanced students interested in cutting-edge research in the aforementioned domains.

Contact linguistics is the overarching term for a highly diversified field with branches that connect to such widely divergent areas as historical linguistics, typology, sociolinguistics, psycholinguistics, and grammatical theory. Because of this diversification, there is a risk of fragmentation and lack of interaction between the different subbranches of contact linguistics. Nevertheless, the different approaches share the general goal of accounting for the results of interacting linguistic systems. This common goal opens up possibilities for active communication, cooperation, and coordination between the different branches of contact linguistics. This book, therefore, explores the extent to which contact linguistics can be viewed as a coherent field, and whether the advances achieved in a particular subfield can be translated to others. In this way our aim is to encourage a boundary-free discussion between different types of specialists of contact linguistics, and to stimulate cross-pollination between them.

Semantic change — how the meanings of words change over time — has preoccupied scholars since well before modern linguistics emerged in the late 19th and early 20th century, ushering in a new methodological turn in the study of language change. Compared to changes in sound and grammar, semantic change is the least understood. Ever since, the study of semantic change has progressed steadily, accumulating a vast store of knowledge for over a century, encompassing many languages and language families. Historical linguists also early on realized the potential of computers as research tools, with papers at the very first international conferences in computational linguistics in the 1960s. Such computational studies still tended to be small-scale, method-oriented, and qualitative. However, recent years have witnessed a sea-change in this regard. Big-data empirical quantitative investigations are now coming to the forefront, enabled by enormous advances in storage capability and processing power. Diachronic corpora have grown beyond imagination, defying exploration by traditional manual qualitative methods, and language technology has become increasingly data-driven and semantics-oriented. These developments present a golden opportunity for the empirical study of semantic change over both long and short time spans. A major challenge presently is to integrate the hard-earned knowledge and expertise of traditional historical linguistics with cutting-edge methodology explored primarily in computational linguistics. The idea for the present volume came out of a concrete response to this challenge. The 1st International Workshop on Computational Approaches to Historical Language Change (LChange'19), at ACL 2019, brought together scholars from both fields. This volume offers a survey of this exciting new direction in the study of semantic change, a discussion of the many remaining challenges that we face in pursuing it, and considerably updated and extended versions of a selection of the contributions to the LChange'19 workshop, addressing both more theoretical problems — e.g., discovery of "laws of semantic change" — and practical applications, such as information retrieval in longitudinal text archives.

Do speakers’ identity constructions influence the emergence of new varieties of a language? This question is at the heart of a debate about how the process of the emergence of postcolonial varieties of English can best be modeled. This volume contributes to the debate by linking it to models and theories proposed by anthropological linguists, sociolinguists and discourse linguists who view identity as a social and cultural phenomenon that is produced through linguistic and other social practices. Language is seen as essential for identity constructions because speakers use linguistic forms that index social ‘personae’ as well as specific social practices and values to convey an image of self to other speakers. Based on the theory of enregisterment that models the cultural and discursive process of the creation of indexical links between linguistic forms and social values, the argument is made that any model of the emergence of new varieties needs to differentiate carefully between a structural level and a discursive level. What emerges on the discursive level as a result of processes of enregisterment is a ‘discursive variety’. The volume illustrates how the emergence of a discursive variety can be systematically studied in a historical context by focusing on the enregisterment of American English as it can be observed in nineteenth-century U.S. newspapers. Using a discourse-linguistic methodological framework and two large databases containing close to 78 million newspaper articles, the study reveals a complex pattern of indexical links between the phonological forms /h/-dropping and -insertion, yod-dropping, a lengthened and backened bath vowel, non-rhoticity, a realization of prevocalic /r/ as a labiodental approximant as well as the lexical items baggage and pants on the one hand and social values centering around nationality, authenticity and non-specificity on the other hand. Qualitative analyses uncover the social personae associated with the linguistic forms (e.g. the American cowboy, the African American mammy and the ‘Anglo-maniac’ American dude), while quantitative analyses trace the development over time and show that the enregisterment processes were widespread and not restricted to a particular region.

It is well-known that contact between speakers of different languages or varieties leads to dynamics in many respects. From a grammatical perspective, especially contact between closely related languages/varieties fosters contact-induced innovations. The evaluation of such innovations reveals speakers’ attitudes and is in turn an important aspect of the sociolinguistic dynamics linked to language contact. In this volume, we assemble studies on such settings where typologically congruent languages are in contact, i.e. language contact within the Germanic branch of the Indo-European language family. Languages involved include Afrikaans, Danish, English, Frisian, (Low and High) German, and Yiddish. The main focus is on constellations where a variety of German is involved (which is why we use the term ‘German(ic)’ in this book). So far, studies on language contact with Germanic varieties have often been separated according to the different migration scenarios at hand, which resulted in somewhat different research traditions. For example, the so-called Sprachinselforschung (research on ‘language islands’) has mainly been concerned with settings caused by emigration from the continuous German-speaking area in Central Europe to locations in Central and Eastern Europe and overseas, thus resulting in some variety of German abroad. However, from a linguistic point of view it does not seem to be necessary to distinguish categorically between contact scenarios within and outside of Central Europe if one thoroughly considers the impact of sociolinguistic circumstances, including the ecology of the languages involved (such as, for instance, German being the majority language and the monolingual habitus prevailing in Germany, but completely different constellations elsewhere). Therefore, we focus on language contact as such in this book, not on specific migration scenarios. Accordingly, this volume includes chapters on language contact within and outside of (Central) Europe. In addition, the settings studied differ as regards the composition and the vitality of the languages involved. The individual chapters view language contact from a grammar-theoretical perspective, focus on lesser studied contact settings (e.g. German in Namibia), make use of new corpus linguistic resources, analyse data quantitatively, study language contact phenomena in computer-mediated communication, and/or focus on the interplay of language use and language attitudes or ideologies. These different approaches and the diversity of the scenarios allow us to study many different aspects of the dynamics induced by language contact. With this volume, we hope to exploit this potential in order to shed some new light on the interplay of language contact, variation and change, and the concomitant sociolinguistic dynamics. Particularly, we hope to contribute to a better understanding of closely related varieties in contact.