It goes without saying that the quality of any research, regardless of the domain of inquiry, depends on the adoption of appropriate, valid and transparent approaches to conducting that research. In other words, decisions regarding research methodology are crucial to any scientific endeavour. Research carried out in the field of second language acquisition (SLA) is no exception. However, if SLA researchers undoubtedly recognize the importance of research methodology, it does not always receive the attention it deserves. Indeed, SLA studies have generally focused on empirical results, with relatively little space dedicated to reflecting on methodological questions and challenges or on theoretical and/or methodological assumptions that inform methodological decisions. And yet Byrnes (Reference Byrnes2013: 825) notes that ‘methodological issues inherently merit a certain level of attention inasmuch as they assure the quality of our work’. She then goes on to state that at this point in time, such issues ‘demand a kind of professional scrutiny that goes directly to the core of what we do and what we know and what we can tell our publics that we know – and not only how we do it’. In other words, reflections on methodology not only serve to influence and guide practical decisions, but they are also necessarily linked to overarching questions of epistemology, ontology and research ethics (see Ortega, Reference Ortega2005: 317 for a discussion of the interrelationship among these questions). Byrnes goes on to observe that more and more publications engage strongly and critically with issues connected to research methodology, justifying what she calls the methodological turn in SLA research. This current special issue of the Journal of French Language Studies participates in this trend.

Although Byrnes’ (Reference Byrnes2013) use of the formulation ‘methodological turn’ is quite recent (she chose this expression to characterize publications that appeared in The Modern Language Journal in 2013), researchers who have highlighted the importance of methodological issues in SLA, as well as the challenges – and sometimes shortcomings – that characterize SLA research, are not entirely absent in the history of the field. For instance, Thomas (Reference Thomas1994) reviewed the way in which proficiency level in a second language (L2) had been determined in articles published between 1988 and 1992 in top SLA journals. Her review revealed that L2 proficiency was ‘sometimes inadequately assessed’ (p. 330), as researchers tended to rely on impressionistic judgements and institutional levels to characterize learners’ proficiency in the L2. Thomas concluded that ‘[i]n certain cases, this compromises empirical claims; in many cases, it limits the generalizability of research results’ (p. 330). More recent methodologically-oriented research on the issue of proficiency assessment in the field has revealed some change in the direction of greater use of objective measures (e.g., Thomas, Reference Thomas, Norris and Ortega2006; Hulstijn, Reference Hulstijn2012; Leclercq, Edmonds, and Hilton, Reference Leclercq, Edmonds and Hilton2014), perhaps in part because of the attention that Thomas (Reference Thomas1994) brought to the issue. A second example of a relatively early discussion of methodology comes from Grosjean (Reference Grosjean1998). In this article, he focused on general methodological and conceptual issues, arguing that many of the contradictory results from SLA research could be due to problems stemming from those issues. He moreover observed that ‘all researchers have to struggle with these issues and [that] finding solutions is a common challenge’ (p. 132). Given that such issues represent both a shared burden and responsibility, and that transparent and honest discussions of these issues could go a long way to understanding what may appear to be mixed and sometimes even contradictory findings, we believe that it is important to provide public space for these important reflections.

We are, of course, not alone in our desire to bring additional attention to issues of research methodology in SLA. The last decade has seen a clear increase in publications whose primary aim is to address methodological questions or to encourage reflection on methodological issues. Among these are publications whose aim is to improve quantitative research practices (e.g., Plonsky, Reference Plonsky2014; Larson-Hall and Plonsky, Reference Larson-Hall and Plonsky2015), publications that advocate for replication research on both practical and theoretical grounds (e.g., Marsden, Mackey, and Plonsky, Reference Marsden, Mackey, Plonsky, Mackey and Marsden2016; Marsden, Morgan-Short, Thompson, and Abugaber, Reference Marsden, Morgan-Short, Thompson and Abugaber2018; Porte and McManus, Reference Porte and McManus2018), and publications that look to shine the light on the impact of specific methodological decisions on knowledge building in the field (e.g., Gudmestad and Edmonds, Reference Gudmestad and Edmonds2018; Leeser and Sunderman, Reference Leeser, Sunderman, Granena, Jackson and Yilmaz2016). In this JFLS special issue, we contribute to this line of research with a collection of five articles that address a variety of methodological issues encountered in studying the acquisition of French as an additional language. Three articles examine the acquisition of French as a foreign language, where French is being learned in a classroom setting in a context where the language is not widely spoken outside of the classroom: Mairano and Santiago examine Italian students learning French in a university setting, Kamerhuber, Pustka and Horvath report on Austrian secondary school students who have been studying French at school for between one and six years, and Laval and Lowe study students at a university in the UK who are enrolled in French classes. The two remaining articles report on studies that focus on learners acquiring French as a second language. More specifically, each looks at different learner populations acquiring French in France: Beaujard and Garcia discuss methodological issues uncovered in their attempt to longitudinally examine the acquisition of written French by deaf children who are already French sign language signers, whereas Saddour details and critiques an interview protocol put in place with a group of Syrian asylum seekers enrolled in French language classes at a French university. Each of the five articles provides a reflection that highlights and exemplifies the importance of methodological reflections and decisions when researching the acquisition of French as an additional language.

The special issue opens with the contribution by Beaujard and Garcia. These authors present an ambitious ongoing corpus-based exploration of how four deaf children who are already signers (of French sign language) acquire written French in a school setting. The methodological challenges addressed by the authors are multiple, running the gambit from practical to theoretical. Practical issues discussed by the authors include the ability to select participants according to predetermined (scientifically justified) criteria (see Saddour, for a similar reflection) and the difficulties that are specific to collecting data in classroom settings in cooperation with institutional partners. From a theoretical point of view, the novelty of this study was the authors’ desire to bring together three different theoretical strands in order to better grasp the interplay of different factors in the emergence of written competence by the children studied: (a) emergent literacy, which explores how literacy develops before formal learning of reading and writing (Joigneaux, Reference Joigneaux2013), (b) a semiological approach as developed by Cuxac (Reference Cuxac2014), and which argues that sign languages are structured by iconicity, and (c) learner lects, an approach borrowed from the field of SLA in which the systematicity of individual interlanguages is particularly central (Klein and Perdue, Reference Klein and Perdue1997). In so doing, the authors were faced with the challenge of elaborating an experimental design that reflected these three perspectives, which had not been brought together previously. The authors provide an in-depth presentation of these challenges while detailing the decisions made with respect to them.

In the second article, Mairano and Santiago explore the potential relationship between lexical competence and pronunciation in a L2. More specifically, they report on an empirical analysis that explores how scores obtained on two measures of vocabulary knowledge correlate (or not) with a variety of pronunciation metrics for a group of Italian learners of French. Results showed a weak relationship between vocabulary size, on the one hand, and a subset of the pronunciation metrics, on the other. In the last part of their article, Mairano and Santiago take a step back and provide a thought-provoking reflection on the methodological challenges associated with SLA research on both lexical competence and pronunciation ability, addressing the issues of statistical power and the validity of measures, among others.

Whereas Mairano and Santiago discuss how the choice of measures may impact the ultimate assessment of pronunciation, Kamerhuber, Pustka and Horvath focus on the impact of tasks used in eliciting data for the study of one aspect of L2 French pronunciation. More specifically, using a cross-sectional design, these authors explore how Austrian school children develop with respect to their pronunciation of the schwa in eight French words and expressions, using four different elicitation tasks: repetition, reading a list, reading two texts and a guided interview. Results clearly showed differences as a function of task, and the authors suggest that the findings from the different tasks are complementary. They thus provide a concrete example of the importance of triangulation in SLA research.

In their article, Laval and Lowe adopt a psycholinguistic approach to the study of the acquisition of the French Imperfect by university learners in the UK. In particular, they explore the impact of Processing Instruction (as opposed to what they refer to as traditional instruction) on how learners process the imperfect in real time. Processing Instruction is a pedagogical approach to grammar instruction that seeks to improve form-meaning connections made by learners. This is done by attempting to alter existing processing strategies used by learners to comprehend L2 input (VanPatten, Reference VanPatten1996). Previous research into Processing Instruction has largely relied on off-line measures, and Laval and Lowe argue that tools such as eye-tracking have the potential to provide more fine-grained evidence of changes in on-line processing. They present results from a pre-test/post-test treatment study in which one group of learners received Processing Instruction and the other traditional instruction targeting the imperfect. Results show a clear change in processing behaviour after treatment only for those students who received Processing Instruction. In addition to this empirical study, the authors offer a concise practical guide to conducting eye-tracking research, focusing on concrete methodological and design issues.

In the last article, Saddour reports on the pilot testing of a semi-guided interview protocol. In the pilot phase she reports on, interviews were conducted with nine Syrian asylum seekers in French, and interactions between the interviewer and the interviewee were analysed for a subset of the questions. This analysis aimed to identify potential problems with the interview protocol in order to improve the instrument for the main study. After discussing the empirical data, Saddour presents an honest and stimulating reflection on the use of semi-guided interviews to collect L2 data more generally and with a group of asylum seekers more specifically. She identifies mistakes made in the pilot study and offers tips on how to avoid such pitfalls, tips that other researchers will certainly find helpful.

Through this special issue, we set out to provide a venue for exchange and reflection on questions surrounding research methodology in SLA with a focus on the acquisition of French. The goal of the special issue was to identify methodological issues that deserve attention and discussion, as well as responses that have the potential to help advance practices in the field. We hope that these methodologically-focused articles will resonate with the readers of JFLS, and will contribute to drawing attention to issues concerning the relationship among theory, practice and design that is at the core of research methodology.