A long-standing concern in the field of second language acquisition is that replication studies are not only infrequent but also poorly designed, reported, and labeled. This special issue responds to an urgent need for action by showcasing eleven high-quality replication studies. In doing so, this collection highlights exemplary standards in replication study design and reporting. This introduction to the special issue provides readers with a point of reference for what replication research is, including why replication studies are needed, issues about originality and innovation in replication research, how replication studies can be designed and conducted, and recent advances and resources to support future replication efforts in the field. The introduction concludes with an overview of each study in the special issue, highlighting its main components and discussing how the replication strengthens the field and advances knowledge and understanding about the topic.

Twenty-five years ago, the publication of an article by Pallier, Colomé, and Sebastián-Gallés (2001) launched a new and rapidly evolving research program on how second language (L2) learners represent the phonological forms of words in their mental lexicons. Many insights are starting to form an overall picture of the unique difficulties for establishing functional and precise phonolexical representations in L2; however, for the field to move forward it is pertinent to outline its major emerging research questions and existing challenges. Among significant obstacles for further research, the paper explores the current lack of theoretical agreement on the concept of phonolexical representations and the underlying mechanism involved in establishing them, as well as the variable use of the related terminology (e.g., fuzziness and target-likeness). Methodological challenges involved in investigating phonological processing and phonolexical representations as well as their theoretical implications are also discussed. To conclude, we explore the significance of L2-specific phonological representations for the bottom-up lexical access during casual, conversational speech and how our emerging knowledge of L2 lexical representations can be applied in an instructional setting as two potentially fruitful research avenues at the forefront of the current research agenda.

This study investigates how second language (L2) learners engage in prediction based on their processing goals. While prediction is a prominent feature of human sentence comprehension in first–language speakers, it remains less understood when and how L2 learners engage in predictive processing. By conducting a visual–world eye–tracking experiment involving Chinese–speaking L2 learners of Korean, we tested the hypothesis that L2 learners determine whether to engage in prediction by evaluating the costs and benefits of anticipatory processing. The experiment specifically focused on the impact of a top–down comprehension goal for L2 learners’ predictive use of an honorific form in Korean by providing them with different types of task instruction. Our results indicated that all groups engaged in predictive processing in early and entire predictive regions. However, in the late predictive region, L2 learners presented with a prediction–oriented task, but not those with a simple comprehension task, actively generated expectations about the honorific status of an upcoming referent. These findings lend support to the utility account of L2 prediction, suggesting that L2 learners’ engagement in prediction depends on their current goals and strategies for processing efficiency.

The present study aims to meta-analyze the reliability of second language (L2) reading assessments and identify the potential moderators of reliability in L2 reading comprehension tests. We examined 3,247 individual studies for possible inclusion and assessed 353 studies as eligible for the inclusion criteria. Of these, we extracted 150 Cronbach’s alpha estimates from 113 eligible studies (years 1998–2024) that reported Cronbach’s alpha coefficients properly and coded 27 potential predictors comprising of the characteristics of the study, the test, and test takers. We subsequently conducted a reliability generalization (RG) meta-analysis to compute the average reliability coefficient of L2 reading comprehension tests and identify potential moderators from 27 coded predictor variables. The RG meta-analysis found an average reliability of 0.79 (95% CI [0.78, 0.81]). The number of test items, test piloting, test takers’ educational institution, study design, and testing mode were found to respectively explain 16.76%, 5.92%, 4.91%, 2.58%, and 1.36% of variance in reliability coefficients. The implications of this study and future directions are further discussed.

This study closely replicates Wong, Zhao, & MacWhinney (2018), who found that cognitive linguistics–inspired instruction (i.e., schematic diagram feedback) demonstrated a superiority effect over traditional instruction (i.e., rule and exemplar feedback or corrective feedback) on the translation test but not the cloze test. While the original study adopted the null hypothesis testing approach, the current study adopted Bayesian mixed effects logistic models to investigate how different variables might affect the learnability of prepositions among 81 Chinese-speaking learners of English. The research design, materials, and procedure are nearly identical to those of the original study except for an added delayed posttest. Our findings are generally consistent with the results reported in the original study, indicating that the cognitive linguistics–informed instruction demonstrates superiority effect. Furthermore, these positive learning outcomes persist over time, as evidenced by the results of the delayed posttest.

Al-Hoorie et al. (2024: Studies in Second Language Acquisition, 1–23) illuminate a validation crisis within the second language (L2) Motivational Self System (L2MSS), revealing empirical flaws in its current measurement. Their analysis indicates a persistent lack of discriminant validity among the system’s constructs, issuing a fundamental challenge in distinguishing the concepts. These findings, echoing previous concerns, underscore a pressing need for theoretical refinement and methodological rigor within the field, leading the authors to advocate for a temporary halt in L2 self-studies to address these issues comprehensively. This commentary discusses the call for a substantive moratorium presented by Al-Hoorie et al. (2024: Studies in Second Language Acquisition, 1–23) as a necessary step toward resolving persistent challenges in the field. By highlighting historical issues and suggesting pathways for theoretical diversification and methodological advancement, I aim to foster a productive dialogue on motivational psychology in language learning while ensuring empirical robustness.

People are frequently concerned about the impressions they make on others (referred to as metaperceptions), but their insights are often inaccurate. Illustrating the phenomenon called the liking gap, speakers interacting in their first language (L1) and second language (L2) tend to underestimate how much they are liked by their interlocutor, and these judgments often predict their desire to engage in future interaction and collaboration. To understand the scope of this bias and its consequences, we focused on L1–L2 dyadic interaction, examining metaperception as a potential barrier to conversations between university students. We recruited 58 previously unacquainted university students to perform a 10-min academic discussion task between one L1 and one L2 speaker. Afterward, the speakers (a) assessed each other’s interpersonal liking, speaking skill, and interactional behavior; (b) provided their metaperceptions of their interlocutor’s assessments of the same dimensions; and (c) estimated their interest in future interaction with the same interlocutor. All speakers showed a reliable metaperception bias to underestimate their interpersonal liking, speaking skill, and interactional behavior. However, only L1 speakers’ desire to engage in future interaction was associated with their metaperceptions of interpersonal liking. We discuss implications of this finding for understanding and promoting academic communication.

Is it possible to acquire a sensitivity to a regularity in language without intending to and without awareness of what it is? In this conceptual replication and extension of an earlier study (Williams, 2005) participants were trained on a semiartificial language in which determiner choice was dependent on noun animacy. Participants who did not report awareness or recognition of this rule were nevertheless above chance at selecting the correct determiner in novel contexts. However, further analyses based on trial-by-trial subjective judgments and item similarity statistics were consistent with the possibility that responses were based on conscious feelings of familiarity or analogy to trained items rather than unconscious knowledge of a semantic generalization. The results are discussed in terms of instance-based approaches to memory and language, and the implications for the concept of “learning without awareness” are considered.

Theories of learning and attention predict a positive relationship between reading times on unfamiliar words and their learning; however, empirical findings of contextual learning studies range from a strong positive relationship to no relationship. To test the conjecture that longer reading times may reflect different cognitive and metacognitive processes, the need to infer novel word meanings from context was deliberately manipulated. One hundred and two adult first– and second–language English language speakers read sixty passages containing pseudowords while their eye movements were recorded. The passages were either preceded or followed by pseudoword definitions. After reading, participants completed posttests of cued meaning recall and form recognition. Meaning recall was positively associated with (i) individual cumulative reading times and (ii) participants’ general vocabulary knowledge, but not when definitions were provided before reading. Form recognition was unaffected by cumulative reading times. Our findings call for a cautious approach in making causative links between eye–movement measures and vocabulary learning from reading.

Over the past decades, bilingualism researchers have come to a consensus around a fairly strong view of nonselectivity in bilingual speakers, often citing Van Hell and Dijkstra (2002) as a critical piece of support for this position. Given the study’s continuing relevance to bilingualism and its strong test of the influence of a bilingual’s second language on their first language, we conducted an approximate replication of the lexical decision experiments in the original study (Experiments 2 and 3) using the same tasks and—to the extent possible—the same stimuli. Unlike the original study, our replication was conducted online with Dutch–English bilinguals (rather than in a lab with Dutch–English–French trilinguals). Despite these differences, results overall closely replicated the pattern of cognate facilitation effects observed in the original study. We discuss the replication of outcomes and possible interpretations of subtle differences in outcomes and make recommendations for future extensions of this line of research.

High variability phonetic training using perceptual tasks such as identification and discrimination tasks has often been reported to improve L2 perception. However, studies comparing the efficacy of different tasks on different measures are rare. Forty-four Catalan/Spanish bilingual learners of English were trained with identification or categorical discrimination tasks and were tested on both measures. Results showed that both methods were successful in improving the identification and discrimination of English vowels. Training with nonword stimuli generalized to new nonwords and real word stimuli, and improvement was maintained four months later. Cross-task effects may be related to the categorical nature of the discrimination task, which may entail a level of processing similar to that of identification training. Interestingly, whereas identification training improved identification more than discrimination training, discrimination training did not enhance discrimination more than identification training. This asymmetry may be explained by task differences in the amount and type of feedback used.

Based on correlational and factorial analysis of data collected from 384 middle and high school students in South Korea, Al–Hoorie et al. (2024) claimed the existence of a discriminant validity crisis within the L2 motivational self-system research tradition and advocated for abandoning research in this area. In this response, we critically examined the evidence presented, re-analyzed their data, and argued that their findings actually support the discriminant validity of the target scales. We also discussed issues related to the design and implementation of their study and refuted their assertion regarding a discriminant validity crisis in this field. Finally, we emphasized the necessity of prioritizing definitional validity in the ongoing methodological reforms of L2 motivation research.

This paper reports a replication of part of Tavakoli and Foster’s (2008) investigation into the influence of narrative task design on second language (L2) oral performance. The initial study found in part that narratives with both foreground and background information elicited significantly greater syntactic complexity than those with only foreground information. This close replication adds the variable of literacy, conducting the study with adult refugees to New Zealand with low first language (L1) literacy. Participants narrated two of the four cartoon strips in Tavakoli and Foster (2008). In contrast to the initial study, background information in the narrative tasks had no impact on the syntactic complexity, lexical diversity, or fluency of performances. However, given the tendency of participants to omit background events, this outcome is discussed in terms of visual literacy, and aptness to describe rather than connect the cartoon frames. The implications for the use of narrative tasks with such learners are explored.

This study examines the effects of task complexity on second language (L2) pronunciation accuracy and global pronunciation measures in pronunciation-unfocused tasks and assesses the relationship between acoustic and listener-based pronunciation measures. Eighty-two Catalan/Spanish learners of English performed simple and complex versions of a problem-solving monologic speaking task, for which the oral stops /p, t, k/ and vowel contrasts /iː/-/ɪ/ and /æ/-/ᴧ/ were embedded in the lexical items used to perform the task. Pronunciation accuracy was gauged through acoustic measurements of laryngeal timing (voice onset time), vowel contrastiveness and nativelikeness (Mahalanobis distances), and native speakers’ ratings of comprehensibility and accentedness. Results revealed detrimental effects of increased task complexity on the productions of oral stops and speech comprehensibility and accentedness; however, no consistent task complexity effects were found on vowel accuracy. The analysis also revealed an association between segmental accuracy and global dimensions of L2 speech.

This study aimed to investigate the relationship between lexical coverage and TV viewing comprehension. Previous studies have indicated that 95% to 98% of lexical coverage may be needed for reading comprehension (Hu & Nation, 2000). To understand informal listening passages, lower coverage figures (95%-90%) may suffice. However, no study has researched the lexical coverage needed to understand audiovisual texts. We adopted a counter-balanced within-participants design, in which 5%, 10%, or 20% of the words in four 2-min documentaries were replaced with nonwords. Native and non-native speakers of English participated in this study. Results showed that comprehension scores decreased as lexical coverage decreased; comprehension at 100% coverage was significantly higher than 90% and 80% in the two groups; and optimal adequate comprehension is achieved with an optimal lexical coverage of 95%, whereas minimal adequate comprehension is reached with a minimal lexical coverage of 80%.

An important issue in second-language acquisition concerns the role of explicit information (EI) and how it is affected by individual differences. The present study explored this question through a partial replication and extension of Fernández (2008: Experiment 2), which investigated the effects of EI in processing instruction (PI) for the Spanish present subjunctive. This replication compared training with EI (PI) to training without it (structured input; SI). In addition to methodological changes that balance the amount of exposure between groups, this study also includes a control group that received exposure to the target form (C+). Extending the original study, we also assessed the durability of training and whether its effects interact with individual differences in working memory (WM). Results indicate advantages for the PI group during training, supporting Fernández’s conclusions. Immediate post-tests show advantages for the PI group that are not sustained on delayed post-tests. Analyses also indicate benefits for higher WM but only for the PI and C+ groups, although this was only sustained for the C+ group. Thus, findings indicate that when paired with SI, EI and high WM may influence the initial learning of the Spanish subjunctive, but their influence may dissipate over time.

The last three decades have seen significant development in understanding and describing the effects of task complexity on learner internal processes. However, researchers have primarily employed behavioral methods to investigate task-generated cognitive load. Being the first to adopt neuroimaging to study second language (L2) task effects, we aimed to provide novel insights into the neural correlates of task-related variation in L2 oral production. To advance research methodology, we also tested the utility of a neuroimaging technique, functional magnetic resonance imaging (fMRI), in examining the impact of task-related variables on L2 speech production when combined with cognitive–behavioral tools (speech analysis, expert and learner judgments). Our research focus was the effects of task complexity on silent pausing. Twenty-four Japanese learners of English completed eight simple and complex versions of decision-making tasks, half in their first language and half in their L2. The dataset for the present study included the L2 speech and fMRI data, expert judgments, and participants’ difficulty ratings of the L1 and L2 tasks they completed. Based on our findings, we concluded that brain imaging and L1 task difficulty ratings were more sensitive to detecting task complexity effects than L2 self-ratings and pausing measures. These results point to the benefits of triangulating cognitive and neural data to study task-based neurocognitive processes.

Despite accumulating evidence, accounts for the efficacy of reading-while-listening (RWL) in facilitating vocabulary learning are largely unexamined, hindering a thorough understanding of the reasons underlying the usefulness of such bimodal input. In this article, we report a close replication of Malone (2018), purposefully manipulating the participants’ native language background to shed light on whether the auditory component in RWL promotes spoken-written form mappings. One hundred and eighty-eight English learners from Austria, Belgium, Hong Kong, and Beijing read or read and listened to four stories containing target words for learning. They completed two surprise vocabulary tests and two assessments of working memory capacity. We only replicated a correlation between working memory capacity and the form recognition test reported in the initial study. Thanks to our manipulation, we discovered an important role of L1 background in the effectiveness of RWL for form recognition knowledge. We discuss the implications for RWL research.

This study aimed to closely replicate Wiseheart et al. (Bilingualism: Language and Cognition, 19(1), 141–146, 2016) by investigating the transferability of language-switching skills to nonlinguistic task switching. Current evidence is mixed and there is a need to conduct robust replications in this area. Bilingual (n = 31) and monolingual (n = 47) young adults characterized stimuli by either colour or shape based on a given cue. Modifications include online data collection (as opposed to in-person) and adapting the nonverbal intelligence test used. All other aspects of the study mirror those by Wiseheart et al. Results indicate that the bilinguals exhibited better cognitive flexibility in task switching, as evidenced by a reduced global switch cost compared with monolinguals. In contrast, mixed evidence was found for local switch costs. Findings mirror those reported by Wiseheart et al. and suggest that by employing comparable task-switch paradigms and recruiting samples matched on several key variables, including age, gender, variety of languages spoken, and use of English, bilingualism does seem to confer broader executive function advantages. Findings are discussed in relation to theoretical implications to inform future replication studies and advance the bilingual advantage in the switching debate.