Variation is increasingly celebrated as a ‘core explanandum’ (Adger &Trousdale Reference Adger and Trousdale2007: 274) in linguistics. What is more, linguistic variation is popular not only among researchers, but also among students. Against this backdrop, the book under review aims to cater to both professional linguists and students by sketching the many ways of, and reasons for, collecting, analysing and explaining variable data in different domains, such as phonology and syntax. In this endeavour, the book is specifically concerned with variation in English, although the methodologies and interpretational approaches presented in the collection are certainly applicable to other (European-type) languages as well. The twelve chapters in the volume are written by leading experts in the field, and explore linguistic variation from both a methodological and a theoretical perspective. The volume sets the stage with a readable and inspiring general introduction (‘Introduction. Analysing variation in English: what we know, what we don't, and why it matters’), in which the editors summarise the goals of the volume.

The papers in part I of the volume (‘Investigating variation in English: how do we know what we know?’) present and compare methods for collecting and analysing variation data. In this spirit, chapter 1 on ‘Collecting data on phonology’ by Erik R. Thomas sketches ways to explore phonological variation in dialectal and sociolectal data. Issues and data sources discussed include dialect atlas projects (such as the Survey of English Dialects), sociolinguistic interviews, the problem of transcription, acoustic analysis methods, data analysis via, for example, Varbrul, and some recurring issues of special concern in the literature, such as phonological mergers. Chapter 2 (‘How to make intuitions succeed: testing methods for analysing syntactic microvariation’) by Isabelle Buchstaller and Karen Corrigan scrutinises a variety of questionnaire-based approaches (such as reformulation tasks, the direct and indirect grammatical judgement test, pictorial elicitation tasks and magnitude estimation tasks) to measure intuitions about grammatical acceptability across speakers of different dialects. To illustrate these designs, the authors report a very interesting (though somewhat sobering) pilot study conducted in the north-east of England which shows that different tests do not necessarily yield consistent results. By contrast to chapter 2, chapter 3 (‘Corpora: capturing language in use’) by Alexandra D'Arcy is concerned with the use of naturalistic text corpora to study linguistic variation. The chapter initially contrasts ‘conventional’, i.e. more or less representative and publicly available corpora (such as the British National Corpus) with ‘unconventional’, i.e. more specialised and private corpora, which – despite the issues of replicability they pose – are widely used in variationist sociolinguistics, for example. The chapter subsequently discusses a number of pertinent issues in corpus linguistics, such as corpus design, representativeness, annotation, and using the World Wide Web as a corpus. Chapter 4 (‘Hypothesis generation’) by Hermann Moisl is, at base, a case study highlighting how one particular exploratory statistical analysis technique, Hierarchical Agglomerative Cluster Analysis, can be marshalled to generate hypotheses on the basis of a complex, multivariate data set describing phonological variability in the Newcastle Corpus of Tyneside English (NECTE). In chapter 5 (‘Quantifying relations between dialects’) by Warren Maguire and April McMahon we find a comprehensive survey of how researchers have gone about measuring the degree of relatedness between linguistic varieties. Issues and approaches canvassed include the traditional isogloss method, which views relatedness as a function of the number of shared features; dialectometry in the spirit of Hans Goebl and John Nerbonne, which is computationally intensive and calculates aggregate distances and similarities between many varieties on the basis of many features; lexicostatistics on the basis of core vocabulary lists; the use of Levenshtein distance to calculate phonetic distance; the ‘Sound Comparison’ method developed in Edinburgh (e.g. McMahon et al. Reference McMahon, Heggarty, McMahon and Maguire2007); and validation techniques, for example on the basis of perceptual dialectology experiments. The chapter also features a very readable introduction to techniques designed to visualise relatedness between varieties. In chapter 6 (‘Perceptual dialectology’), Chris Montgomery and Joan Beal review work in the perceptual dialectology tradition, which studies folk perceptions of, and attitudes towards, dialect variation. Montgomery and Beal review seminal work by, for example, Dennis Preston, and subsequently go on to sketch how the perceptual dialectology paradigm can be fruitfully applied to dialect variability in the UK.

The chapters in part II of the volume (‘Why does it matter? Variation and other fields’) spell out why the study of linguistic variation is theoretically interesting to a number of fields, within linguistics and beyond. Patrick Honeybone, in chapter 7 (‘Variation and linguistic theory’), explores the status of linguistic variation in formal, generative linguistics in the tradition of Noam Chomsky (the chapter title is therefore a bit misleading, as for instance variationist linguistics is every bit as theoretical as Chomskian linguistics). Honeybone argues that as far as formal theorising is concerned, it is crucial to distinguish between inter-speaker and intra-speaker variation. The remainder of the chapter is more or less dedicated to the question of how many mental grammars it takes to explain linguistic variation, reviewing work by Anthony Kroch and David Lightfoot, among others. Gregory Guy's contribution (chapter 8, ‘Variation and change’) discusses the variationist sociolinguistics take on variation, which – in a nutshell – argues that language variation and language change are essentially two different sides of the same coin. In addition to explaining crucial notions in the variationist sociolinguistics enterprise (key words: orderly heterogeneity, inherent variability, change from above/below, social factors, real and apparent time, and so on), Guy also addresses the interface between Optimality Theory and variationist sociolinguistics, and the role that Exemplar Theory plays in recent approaches. Chapter 9 (‘Variation and forensic linguistics’) by Frances Rock explains how linguistic variation is relevant to legal problems. The chapter considers two questions: first, how does linguistic variation bear on the functioning of legal systems, given that laws are encoded through language? Here, the reader learns, among other things, about issues of code choice by interactants in legal settings. Second, how can variation analysis provide linguistic evidence in criminal cases? In this realm, the contribution sketches approaches in forensic phonetics (e.g. speaker profiling) and authorship attribution approaches. Emma Moore, in chapter 10 (‘Variation and identity’), outlines the currently very fashionable ‘Third Wave’ approach to variation studies pioneered by Penny Eckert, which focuses on the role of identity in linguistic variation, and on how linguistic variables come to have the social meanings that they do. Moore discusses the role that concepts such as ‘style’ and ‘community of practice’ play in Third Wave sociolinguistics, and shows – aptly drawing on a number of case studies – how Third Wave sociolinguists are interested in the construction of personae, rather than in correlations between linguistic variables and demographic speaker characteristics. Chapter 11 by Rob McMahon (‘Variation and populations’) is one of the highlights of the book. McMahon is a molecular geneticist, and the chapter examines the extent to which biological and genetic variation (thanks to population interaction) may correlate with (contact-induced) linguistic variation. At the outset, the chapter offers a patient and readable introduction to key concepts in genetics (‘populations’, genotypes, mutation, selection, genetic markers, and so forth). Next, McMahon demonstrates how we may draw on genetic clues to better understand the history of English. For example, contrary to assumptions in the literature, genetic evidence actually speaks against widespread genocide of Celtic speakers in Britain upon the Germanic invasions in the fifth and sixth centuries AD. Therefore, the absence of substantial Celtic influence on Early English must have had social reasons. As a matter of fact, the genetic evidence discussed lends credibility to claims according to which English grammar may be more indebted to Celtic influences than has been traditionally assumed. Chapter 12 (‘Variation and education’) by Graeme Trousdale rounds off the volume by highlighting how, on the one hand, research into variation in English can inform educational policy making and curriculum design while, on the other hand, collaboration between variation scholars and educators can tap into the classroom as an exciting data source to study variation.

The volume, then, offers a quite comprehensive, yet coherent, collection of extremely well-written and accessible chapters that review theoretical and practical issues in variation research. Inevitably, some readers may find individual chapters less indispensable than others; at the same time, as always it is clear that more chapters could have been added – for example, the present reviewer would not have objected to chapters explicitly dedicated to variation from a psycholinguistic (in the spirit of, e.g., Jaeger Reference Jaeger2006), historical (e.g. Nevalainen & Raumolin-Brunberg Reference Nevalainen and Raumolin-Brunberg2003), or probabilistic grammar (e.g. Bresnan & Ford Reference Bresnan and Ford2010) perspective. That said, the major topics in English variation research are no doubt covered, and since the volume appears to be a tad UK-centric – entirely legitimately so – the choice of chapter topics and authors may indeed have been deliberate. The volume includes a helpful index, and as an added bonus each chapter in the volume ends in a helpful ‘Where next?’ section, in which the reader is pointed to further reading and issues that await research – for instance, in dissertation research. In all, the book is required reading for researchers wishing to learn about the state of the art in English variation studies, and it should also serve as an excellent resource in advanced undergraduate and postgraduate courses on linguistic variation in English.