This paper puts forward a research agenda in the area of explicit and implicit knowledge and learning of second or additional languages. Based on a brief overview of reliable findings as well as open questions in the field, three agenda items are highlighted. First, valid and reliable measures of explicit and, in particular, implicit knowledge and…

Against the backdrop of greater emphasis on learner centredness and growing attention to learners' voices in recent decades, concerns have been raised over researchers' dominance in shaping research scope and findings. Whether it be quantitative, qualitative, or mixed-methods research, learners' voices are mostly absent at the methodological…

Nowadays, research in second language acquisition (SLA) is becoming increasingly interdisciplinary while many technical frontiers and research hotspots have emerged. Many studies focus on interdisciplinary topics, but few in-depth studies have been conducted on interdisciplinarity. This study examined the interdisciplinarity of SLA and the…

Structural equation modeling (SEM), as a flexible and versatile multivariate statistical technique, has been growingly used since its introduction in the 1970s. This article presents a methodological synthesis of the characteristics of the use of SEM in L2 research by examining the reporting practices in light of the current SEM literature to…

In this brief report, we present a scoping review of 31 second language (L2) vocabulary research syntheses published in the Web of Science from January 1990 to May 2022. The purpose of this undertaking was to understand what L2 vocabulary research synthesizers have aggregated and the investigative foci they intended to address. It was observed…

Adopting Complex Dynamic Systems Theory (CDST) in Second Language Acquisition (SLA) is a testament to the revolutionary and evolutionary advancement in theory and empirical practice in the field. CDST is revolutionary for the fact that it warrants systems thinking of SLA phenomena that breaks the chain of dichotomous conceptualization on vital…

We present a review of second language researchers' use of cluster analysis, an advanced statistical method still uncommon but increasingly used to identify groups or patterns in a dataset and to examine group differences. After describing key methodological considerations in conducting cluster analysis, we present a methodological synthesis of 65…

Replication is a research methodology designed to verify, consolidate, and generalize knowledge and understanding within empirical fields of study. In second language studies, however, reviews share widespread concern about the infrequency of replication. A common but speculative explanation for this situation is that replication studies are not…

At the turn of the new millennium, in an article published in "Language Teaching Research" in 2000, Dörnyei and Kormos proposed that 'active learner engagement is a key concern' for all instructed language learning. Since then, language engagement research has increased exponentially. In this article, we present a systematic review of 20…

Research on input processing and processing instruction has often employed a scoring method known as trials to criterion to observe the effects of instruction that emerge during training. Despite its common use in this research (see Fernández, 2021) this metric has never been evaluated critically. The present study first discusses several…

Statistical tests carry with them a number of assumptions that must be checked. Failing to do so and to report the results of such preliminary analyses introduce a potential threat to the internal validity of a study and to our ability as consumers to put faith in study findings. This article systematically examines the reporting of checks on…

The study of language maintenance and shift (LMS) has attracted a large body of empirical work in language policy and planning (LPP) contexts, including allochthonous (immigrant) and autochthonous (indigenous) languages. However, some critical ontological questions that relate to the scope and terminology of language maintenance studies remain…

Language is on display all around us, all the time, and the study of this linguistic landscape is one of the fastest-growing areas of research in applied linguistics. This book provides an overview of how the field of Linguistic Landscape Studies has emerged and developed over the past 20 years, combined with an in-depth exploration of the…

First, we trace the history of second language acquisition (SLA) from early stages in the mid-twentieth century to today. We next consider the status of the field in today's research world with a particular focus on all aspects of methodology and, finally, we take a look at the future and discuss issues related to scientific rigor in light of Open…

Recent studies on language and migration have attempted to address the social injustices stemming from global disparities in wealth and opportunities. However, there's a risk of researchers unintentionally reinforcing traditional power dynamics, positioning themselves in power while reducing participants to mere data sources. Focusing on migrants…