This article reviews three types of measures which have been widely used in psychological research to assess the conscious or unconscious status of knowledge: retrospective verbal reports, direct and indirect tests, and subjective measures. The goal is to make these techniques available to a wide audience of second language (L2) researchers and to offer suggestions for their sound use in order to promote the study of implicit L2 learning. Each section begins with a brief definition of what it means to have acquired unconscious (implicit) knowledge according to the measure in question. This is followed by a description of representative studies that illustrate how the technique has been used and by a discussion of its limitations. Each section concludes with specific guidelines on how to apply the respective measure to the investigation of implicit and explicit L2 learning.

This study constitutes the first statistical analysis to employ a Bayesian multinomial probit model in the investigation of subject expression in first and second language (L2) Spanish. The study analyzes the use of third-person subject-expression forms and demonstrates that the following variables are important for subject expression: perseveration, switch reference, number of the verb, specificity, verbal tense/mood/aspect, object pronoun, referent cohesiveness, the interaction of switch reference and referent cohesiveness, and the interaction of native language and four independent variables (number, specificity, tense/mood/aspect, and object pronoun). However, only certain parameters of these independent variables predicted use. The analysis highlights that, for advanced L2 speakers and native speakers, all forms of subject expression (i.e., lexical noun phrases, null subjects, personal pronouns, and other pronouns) allow variation and should be examined for a thorough understanding of subject expression in Spanish. The study offers theoretical and empirical evidence for the need to conduct cross-disciplinary research in second language acquisition.

Recent theorizing on second language (L2) motivation has proposed viewing motivation as a function of the language learners’ vision of their desired future language selves. This would suggest that the intensity of motivation is partly dependent on the learners’ capability to generate mental imagery. In order to test this hypothesis, this study investigates whether learner characteristics are related to sensory and imagery aspects with indices of the strength of the learners’ future L2 self-guides (ideal and ought-to L2 selves) and how these variables are linked to learning achievement in two target languages, English and Mandarin, assessed both by self-report and objective measures. One hundred seventy-two Year 8 Chinese students (ages 13–15) completed a questionnaire survey, and the results reveal several significant associations between the future self-guides and intended effort and actual grades, including a consistently positive relationship between the ideal self and the criterion measures. The findings also confirm the multisensory dimension of future self-guides, suggesting the importance of a broad imagery capacity (including both visual and auditory components) in the development of individuals’ future self-identities. Finally, the ideal-self images associated with different languages were shown to form distinct L2-specific visions, which has various implications for future research with regard to the potential positive or negative interaction of these self images.

Researching the longitudinal development of second language (L2) learners is essential to understanding influences on their success. This 7-year study of oral skills in adult immigrant learners of English as a second language evaluated comprehensibility, fluency, and accentedness in first-language (L1) Mandarin and Slavic language speakers. The primary data were judgments at three times from two sets of listeners: native monolingual speakers of English and highly proficient English L2 speakers. The Mandarin L1 speakers showed no change over time on any of the dimensions, while the Slavic language L1 speakers improved significantly in comprehensibility and fluency. Improvement in accent was limited to the first 2 years in the Slavic language group. These outcomes appear to be due to the complex interplay of L1, age, the depth and breadth of learners’ conversations in English, and their willingness to communicate.

Previous research has demonstrated substantially improved second language (L2) vocabulary learning when spoken word forms are varied using multiple talkers, speaking styles, or speaking rates. In contrast, the present study varied visual representations of referents for target vocabulary. English speakers learned Spanish words in formats of no variability (6 repetitions, 1 image of the word referent), moderate variability (2 repetitions each of 3 different images), and high variability (1 repetition each of 6 different images). In contrast to the positive effects of word-form variability, referent token variability produced negative effects on L2 vocabulary learning. These findings support the type of processing resource allocation model (Barcroft, 2002) because increases in referent-oriented processing diverted available resources from form-oriented processing and learning.

This study considers the role of verbal working memory in sentence comprehension in typically developing English-speaking children. Fifty-six (N = 56) children aged 4;0–6;6 completed a test of language comprehension that contained sentences which varied in complexity, standardized tests of vocabulary and nonverbal intelligence, and three tests of memory that measured the three verbal components of Baddeley's model of Working Memory (WM): the phonological loop, the episodic buffer, and the central executive. The results showed that children experienced most difficulty comprehending sentences that contained noncanonical word order (passives and object relative clauses). A series of linear mixed effects models were run to analyze the contribution of each component of WM to sentence comprehension. In contrast to most previous studies, the measure of the central executive did not predict comprehension accuracy. A canonicity by episodic buffer interaction showed that the episodic buffer measure was positively associated with better performance on the noncanonical sentences. The results are discussed with reference to capacity-limit and experience-dependent approaches to language comprehension.

When speaking to young children, adults adapt their language to that of the child. In this article, we suggest that this child-directed speech (CDS) is the result of a transactional process of dynamic adaptation between the child and the adult. The study compares developmental trajectories of three children to those of the CDS of their caregivers. Furthermore, a mathematical-conceptual model is built that captures the essential dynamics of adaptation in a series of coupled equations. This model is sensitive to changes in the language development of the child. The results show evidence for a dynamic form of adaptation, although there are also clear individual differences.

Despite the consistency with which gender differences have been found in second language motivation, little systematic research has taken place on motivation and gender to date. Permeating self-concept development, gender impacts not only current selves but also future-oriented possible selves. In construing possible selves, females tend to emphasize interdependence, meaning they invest more in interpersonal relationships and self–other interaction. Based on instruments measuring ideal language-speaking/using selves and an interdependent self-construal in a sample of 140 female and 129 male adolescents enrolled in the final year of secondary education in Sweden, and using confirmatory factor analysis, support was found for the hypothesis that gender-related variance on a measure of the ideal language-speaking/using self could be accounted for by an interdependent self-construal. In discussing the results, further avenues for exploring the impact of gender on possible selves using more contextually sensitive research designs are presented.

This article reports a meta-analysis of studies that investigated the relative effectiveness of comprehension-based instruction (CBI) and production-based instruction (PBI). The meta-analysis only included studies that featured a direct comparison of CBI and PBI in order to ensure methodological and statistical robustness. A total of 35 research projects in 30 published studies were retrieved. The studies were coded for three types of effect sizes: comparative, absolute, and pre-to-post change. The comparative effect sizes were used in a subsequent moderator analysis to test the impact of two mediator variables—CBI with and without Processing Instruction and PBI involving text creation versus text manipulation. The results showed that (1) overall, both types of instruction had large effects on both receptive and productive knowledge; (2) for receptive knowledge, CBI had a greater effect than PBI when the acquisition was measured within one week but the difference diminished in the delayed tests (i.e., posttests administered between 1 week and 75 days after the treatment); (3) for productive knowledge, CBI and PBI had similar effects in short-term measurement but PBI was more effective in the delayed tests; and (4) the initial advantage found for CBI was largely due to Processing Instruction. We discuss the theoretical and pedagogical significance of these findings.

This study employed synthetic and meta-analytic techniques to review the literature on the Cognition Hypothesis, which predicts that increasing task complexity influences the quality of second language production. Based on 8 inclusion criteria, 17 published studies were synthesized according to key features. A subset of these studies (k = 9) was also meta-analyzed to investigate the overall effects of raising resource-directing task demands on learner output during monologic tasks. The synthesis of 17 primary studies revealed an assortment of treatments and measures. Among the 9 comparable studies, the meta-analysis uncovered small positive effects for accuracy and small negative effects for fluency. This lends support to the Cognition Hypothesis; however, the present study also disconfirms predictions regarding syntactic complexity. Implications for research and pedagogy are discussed.