L2 Performance Research Articles

Design of switched linear control systems based on Youla parameterization with average dwell time

ABSTRACTA two-steps method of designing switched linear systems is presented with the parameterization of globally uniformly asymptotically stabilising controllers with average dwell time (ADT). First, an observer-based switching controller design is given for a class of switched linear system. Based on the construction of observer-based controller, conceptions of doubly coprime factorization and Youla parameterization of LTI systems are extended to switched linear systems with respect to globally uniformly asymptotical stability (GUAS) using a state-space expression. Second, the parameterization of closed-loop systems, which are affine with any globally uniformly asymptotically stable -parameter, is then described. This description enables the application of the –- parameter approach to a variety of switched linear control-system designs. The control construction provides us a two-steps process design procedure. Above all, based on the Schur complementary lemma and controller variable elimination method, a systematic weighted L2 performance strategy is focused on and a design scheme of to obtain weighted L2-gain performance is clarified. Finally, a numerical example is given to show the validity and potential of the developed results.

The Role of Linguistic Diversity in the Prediction of Early Reading Comprehension: A Quantile Regression Approach

ABSTRACTUsing classical and quantile regression analyses, we investigated whether predictor variables for early reading comprehension differed depending on language background and ability level in a mixed group of 161 monolingual (L1) and bilingual (L2) children in second grade (6–8 years). Although L2 readers scored lower on oral language skills and reading comprehension, the prediction of reading comprehension was similar for L1 and L2 readers. Classical regression identified decoding, vocabulary, and morphosyntactic knowledge as unique predictors with no interaction with language background. Quantile regression demonstrated that the prediction of reading comprehension differed across ability levels; decoding and morphosyntactic knowledge were consistently unique predictors, but vocabulary was uniquely related only for poor comprehenders and working memory only for good comprehenders. In both types of analysis, language background did not explain unique variance, indicating that individual differences in the predictor variables explained the L1–L2 performance gap in early reading comprehension across the ability range.

The Receptive-Expressive Gap in English Narratives of Spanish-English Bilingual Children With and Without Language Impairment.

First, we sought to extend our knowledge of second language (L2) receptive compared to expressive narrative skills in bilingual children with and without primary language impairment (PLI). Second, we sought to explore whether narrative receptive and expressive performance in bilingual children's L2 differed based on the type of contextual support. In a longitudinal group study, 20 Spanish-English bilingual children with PLI were matched by sex, age, nonverbal IQ score, and language exposure to 20 bilingual peers with typical development and administered the Test of Narrative Language (Gillam & Pearson, 2004) in English (their L2) at kindergarten and first grade. Standard scores were significantly lower for bilingual children with PLI than those without PLI. An L2 receptive-expressive gap existed for bilingual children with PLI at kindergarten but dissipated by first grade. Using single pictures during narrative generation compared to multiple pictures during narrative generation or no pictures during narrative retell appeared to minimize the presence of a receptive-expressive gap. In early stages of L2 learning, bilingual children with PLI have an L2 receptive-expressive gap, but their typical development peers do not. Using a single picture during narrative generation might be advantageous for this population because it minimizes a receptive-expressive gap.

Persistent differences between native speakers and late bilinguals: Evidence from inflectional and derivational processing in older speakers

Previous research with younger adults has revealed differences between native (L1) and non-native late-bilingual (L2) speakers with respect to how morphologically complex words are processed. This study examines whether these L1/L2 differences persist into old age. We tested masked-priming effects for derived and inflected word forms in older L1 and L2 speakers of German and compared them to results from younger L1 and L2 speakers on the same experiment (mean ages: 62 vs. 24). We found longer overall response times paired with better accuracy scores for older (L1 and L2) participants than for younger participants. The priming patterns, however, were not affected by chronological age. While both L1 and L2 speakers showed derivational priming, only the L1 speakers demonstrated inflectional priming. We argue that general performance in both L1 and L2 is affected by aging, but that the more profound differences between native and non-native processing persist into old age.

Korean L2 speakers’ regulatory focus and oral task performance

AbstractThe L2 motivation self system posits that motivation emerges from the dynamic interactions among a learner’s ideal L2 self, ought-to L2 self, and situated learning experience. Only a few studies to date have investigated the individual and combined impact of trait-based and task-induced motivation (i. e., situational motivation related to the immediate learning environment) on L2 performance. Therefore, the current study explored whether Korean L2 speakers’ trait-based and task-induced regulatory focus impacted their oral task performance. Vietnamese university students (N=62) studying Korean as a foreign language completed a questionnaire to assess their L2 instrumentality as being oriented toward prevention or promotion. They were randomly assigned to promotion or prevention task-induced conditions, and then carried out an oral task. The results indicated that whereas the participants’ general motivational tendencies did not impact their task performance, the task-induced prevention condition facilitated faster speech rate (i. e., fluency) and lower error rate (i. e., accuracy) than the promotion condition. Implications for further studies are discussed.

Do eye movements reveal differences between monolingual and bilingual children’s first-language and second-language reading? A focus on word frequency effects

An extensive body of research has examined reading acquisition and performance in monolingual children. Surprisingly, however, much less is known about reading in bilingual children, who outnumber monolingual children globally. Here, we address this important imbalance in the literature by employing eye movement recordings to examine both global (i.e., text-level) and local (i.e., word-level) aspects of monolingual and bilingual children’s reading performance across their first-language (L1) and second-language (L2). We also had a specific focus on lexical accessibility, indexed by word frequency effects. We had three main findings. First, bilingual children displayed reduced global and local L1 reading performance relative to monolingual children, including larger L1 word frequency effects. Second, bilingual children displayed reduced global and local L2 versus L1 reading performance, including larger L2 word frequency effects. Third, both groups of children displayed reduced global and local reading performance relative to adult comparison groups (across their known languages), including larger word frequency effects. Notably, our first finding was not captured by traditional offline measures of reading, such as standardized tests, suggesting that these measures may lack the sensitivity to detect such nuanced between-group differences in reading performance. Taken together, our findings demonstrate that bilingual children’s simultaneous exposure to two reading systems leads to eye movement reading behavior that differs from that of monolingual children and has important consequences for how lexical information is accessed and integrated in both languages.

Korean Learners’ L2 Performance in Syntax-Semantics interface : Chinese Wh-Words as Existential Polarity Words

Chen Hui & You, Seok-Hoon. 2018. Korean Learner’s L2 Performance in Syntax-Semantics interface: Chinese Wh-words as Existential Polarity Words. Language Information. Volume 26. 103-128. This study aims to test applicability of the Interface Hypothesis (Sorace & Tsimpli, 2006) in L2 through investigating L2 acquisition of Chinese Wh-Words as Existential Polarity Words (hence force EPWs) by L1 Korean speakers. The present study compares the results of the acceptability judgment test of Chinese EPWs between learner group and native speaker group to investigate 1. Are the interface properties concerning Chinese EPWs and their licensors acquirable by Korea-speaking learners of Chinese? 2. If not, what are the linguistic or non-linguistic effects which cause the interface breakdown? The results show that L2 Chinese learners are unable to establish a complete semantics-syntax relationship with the EPW embedded in the sentence, even at the final state of L2 acquisition. And the results also show that L2 Chinese acquisition is not linear development.

The Effects of Task Complexity and Working Memory on Korean Adult Learners’ English Speaking Performance

This study investigated whether task complexity may affect L2 speaking performance as predicted by the Cognition Hypothesis (Robinson, 2011), and whether the effect of task complexity may interact with individual differences in working memory capacity. A total of twenty Korean advanced-level EFL learners performed two separate picture description tasks, which were different in task complexity along [+/- here and now] dimension. Their working memory was measured by an L1 version of a reading span task. The results showed that there was no significant difference between Here-and-Now task (i.e., a simple task) and There-and-Then task (i.e., a complex task) in terms of complexity, accuracy, and fluency of English speaking performance, rejecting the prediction of the Cognition Hypothesis. Yet, it found that working memory correlated with accuracy in L2 performance on the complex task, but not on the simple task. This indicates that the effect of individual learners’ working memory capacity is observable only when a task demands a high control of attentional resources. Conversely, when a task is simple, individual differences in working memory capacity do not result in significant differences in L2 speaking performance.

Academic proficiency performance in second and third language: the role of school context

ABSTRACTThis study investigated the role of school-related variables in explaining academic proficiency (AP) performance in Hebrew (L2) and English (L3) among immigrant youth. The following sets of variables were examined: (1) school background (2) academic, linguistic and social-psychological support, and (3) professional staff and school resources allocated for immigrant students. The sample included 267 Russian (L1) speaking students drawn from 18 Israeli high schools. Students’ AP level was assessed via AP tests in L2 and L3. Data about the schools were collected through interviews with the school principals. Multivariate analysis of covariance, controlling for socioeconomic status (SES), arrival age and gender indicated that students’ performance significantly varied as a function of the school-related variables although the effect of these variables on students’ AP scores in L2 and L3 was not to the same extent. The variables educational track (comprehensive schools), upper SES, social-psychological support, teacher training, parental involvement, and provision of an immigrants’ class were associated with higher grades in the respective languages whereas provision of academic and linguistic support were related to lower scores. These results highlight the role of the particular learning environment and context as a source of variation in L2 and L3 performance.

On the predictive validity of various corpus-based frequency norms in L2 English lexical processing

The predictive validity of various corpus-based frequency norms in first-language lexical processing has been intensively investigated in previous research, but less attention has been paid to this issue in second-language (L2) processing. To bridge the gap, in the present study we took English as a case in point and compared the predictive power of a large set of corpus-based frequency norms for the performance of an L2 English visual lexical decision task (LDT). Our results showed that, in general, the frequency norms from SUBTLEX-US and WorldLex-Blog tended to predict L2 performance better in reaction times, whereas the frequency norms from corpora with a mixture of written and spoken genres (CELEX, WorldLex-Blog, BNC, ANC, and COCA) tended to predict L2 accuracy better. Although replicated in both low- and high-proficiency L2 English learners, these patterns were not exactly the same as those found in LDT data from native English speakers. In addition, we only observed some limited advantages of the lemma frequency and contextual diversity measures over the wordform frequency measure in predicting L2 lexical processing. The results of the present study, especially the detailed comparisons among the different corpora, provide methodological implications for future L2 lexical research.

Task Complexity, Cognitive Load, and L1 Speech

Relationships among task characteristics, L2 performance, and interlanguage development are of interest both for SLA research and the design of syllabuses and language teaching materials. Complexity has been identified as a promising, but methodologically problematic, task design feature. A study was conducted of the effects of progressive increases in the complexity (operationalized as number of elements) of three versions of each of three tasks on the syntactic complexity and lexical diversity of the speech of 42 English native speakers. Data on native speaker performance are important because they reveal task complexity effects unfiltered by non-native competence. Independent evidence that greater task complexity increased cognitive load was shown by participant self-ratings of perceived difficulty, mental effort, and stress, shorter prospective duration estimates and, using dual-task methodology, slower reaction times. Mid-complex versions of the three tasks elicited the most complex syntactic structures, and the most complex versions elicited the greatest lexical diversity. Implications are noted for the design of parallel studies with non-native speakers, along with suggested methodological improvements for future research with native and non-native populations.

Improving the Validity of L2 Performance Assessments: Use of Many-Facet Rasch Measurement

Improving the Validity of L2 Performance Assessments: Use of Many-Facet Rasch Measurement

Studying texts in a second language: No disadvantage in long-term recognition memory

Despite an increase in bilingualism and the use of English as a medium of instruction, little research has been done on bilingual memory for learnt information. In a previous study, we found an L2 recall cost but equal recognition performance in L2 versus L1 when students studied short expository texts (Vander Beken & Brysbaert, 2017). In this paper, we investigate whether there is a recognition cost after a longer delay, which would indicate that the memory trace is weaker in L2. Results showed equal performance in L1 and L2, suggesting that the recall cost is either located at the production level, or that the levels-of-processing effect is mediated by language, with unaffected surface encoding leading to effectivemarginal knowledgeon the one hand, and hampered deep encoding leading to ineffective (uncued) recall. This paper also contains the Dutch vocabulary test we used for native speakers.

Technology-assisted L2 research in immersive contexts abroad

The recent technological shift in Second Language Acquisition (SLA) research has expanded our understanding of L2 development. Today, SLA research is equally as interested in the product of learning (accuracy) as in the cognitive processes that underlie changes in performance. Technological tools are necessary to investigate both, especially cognitive processes, which are more difficult to identify without precise procedures. The Study Abroad (SA) domain has echoed this trend. SA researchers have sought to explore the influence of the immersive experience on L2 development by combining concurrent data elicitation techniques – latency, eye-tracking, event-related potentials – with assessments of L2 performance, often in conjunction with measures of individual differences. In this article, we examine the contributions from recent cognitively-oriented SA studies that employ these techniques. We also include an overview of other technological resources employed in non-cognitively oriented studies, such as online surveys, blogs (i.e., public discussions and posts meant to be shared), and e-journals (i.e., on-going personal reflections), which have proved useful when answering important question related to learners’ motivation, identity, and intercultural competence. We conclude with recommendations for future research.

Studying texts in a second language: The importance of test type

Little is known about the extent to which information encoding and retrieval differ between materials studied in first and second language (L1 and L2). In this study we compared memory for short, expository texts in L1 and L2, tested with a free recall test and a true/false judgement test. Our results show that students performed at the same level on the recognition test in both languages but not on the free recall test, with much lower performance in L2 than in L1, defined here as the dominant language. The L2 recall cost suggests that students’ performance may be underestimated if they are exclusively tested with essay-type exams in L2.

Relationships among motivation (self-efficacy and task value), strategy use and performance in L2 writing

This paper reports on a study that investigated the relationships among self-efficacy, task value, strategy use and performance in L2 writing. The participants were 304 undergraduate ESL (English as a second language) students in Malaysia. Questionnaires and writing performance tests were used to collect data. Writing performance was determined by a robust testing procedure which is usually employed in high-stakes writing tests. The results showed that four motivational constructs (self-efficacy, intrinsic value, attainment value and cost), and four writing strategy categories (metacognitive, cognitive, affective and effort regulation) were significantly related to writing performance. The study also found that intrinsic value and self-efficacy contributed significantly to the prediction of writing performance after controlling for the other predictor variables of the study. Limitations of the study, directions for future research, and implications for writing instruction and language classroom were discussed.

‘One Task Fits All’? The Roles of Task Complexity, Modality, and Working Memory Capacity in L2 Performance

The present study explores the independent and interactive effects of task complexity and task modality on linguistic dimensions of second language (L2) performance and investigates how these effects are modulated by individual differences in working memory capacity. Thirty‐two intermediate learners of L2 Spanish completed less and more complex versions of the same type of argumentative task in the speaking and writing modalities. Perceived complexity questionnaires were administered as measures of cognitive load to both L2 learners and native speakers to independently validate task complexity manipulations. Task performance was analyzed in terms of general (complexity and accuracy) as well as task‐relevant (conjunctions) linguistic measures. Quantitative analyses revealed that task modality played a larger role than task complexity in inducing improved linguistic performance during task‐based work: Speaking tasks brought about more syntactically complex output while writing tasks favored more lexically complex and more accurate language. In addition, relationships of working memory capacity with various linguistic measures were attested, but only when the cognitive complexity of tasks was enhanced.

Differential Signatures of Second Language Syntactic Performance and Age on the Structural Properties of the Left Dorsal Pathway.

In adult second language (L2) acquisition, individual differences are considerably large even among people with similar experiences. The neural mechanisms underlying this variability would include structural plasticity of language-related pathways. To elucidate such neuroplasticity, we focused on the transitional period of adolescence, which is associated with certain plasticity toward maturation following the sensitive period of language acquisition (≤12 years old). The adolescent brain would thus be influenced by age-dependent factors, as well as performances in L2. Here, we examined individual differences in L2 performances controlling the duration of experience to reveal the differential signatures of performances and age on the plasticity of structural properties in major language-related pathways. We recruited Japanese students at two ages, i.e., junior (age: 13–14) and senior (age: 16–17) high-school students, all of whom started to expose to English at age 12 or 13. We divided them into subgroups, so that either L2 performance [Junior (High)/Senior (Low)] or age [Senior (Low)/Senior (High)] was matched in group comparisons; the duration of L2 experience was also controlled between the Senior (Low) and Senior (High) groups. We then examined the thickness and fractional anisotropy (FA) of the dorsal and ventral pathways, i.e., the arcuate fasciculus (Arcuate) and inferior fronto-occipital fasciculus (IFOF), respectively, using semi-automatic methods for selecting regions without branches. Regarding FA in the left Arcuate, the Senior (High) group showed significantly higher FA than the other two groups, indicating performance-related group differences. Further, FA in the left Arcuate was selectively correlated with the accuracy of a syntactic task. Regarding the thickness of the left Arcuate, the Senior (High) and Senior (Low) groups showed significantly larger thickness than the Junior (High) group, indicating age-related group differences. These differential performance-related and age-related signatures were evident on the left Arcuate alone, in contrast to the right Arcuate that showed only mild differences in thickness, and to the bilateral IFOF that lacked either signature. Our results suggest that the left dorsal pathway continued to develop to adolescence, and that performance differences in a syntactic task can be predicted by its FA, independent of age and the duration of experience.

Three-dimensional Robust Guidance Law with Impact Angle Constraint and Compensation of Channels Coupling

To deal with the coupling between channels in the guidance system for a bank-to-turn missile and the uncertainty of the measurement signal, a novel three-dimensional guidance law with impact angle constraint and compensation of channels coupling is proposed based on the robust control theory. Firstly, lineof- sight rate is described through vector description, and the representation of channels coupling is presented. Secondly, a guidance law which fulfills L2 performance index is designed by taking the measurement uncertainties as exogenous disturbance under the nonlinear robust control theory. A novel form of guidance law is obtained after joining the coupling term. Simulation results show that the proposed robust guidance law can guarantee the integrity of guidance information, also satisfy the requirements of guidance precision and impact angle constraint, and more robust than the traditional guidance law.

The Effects of Different Planning on Complexity, Accuracy, and Fluency in L2 Written Tasks

This study investigates the effects of different planning variants on syntactic complexity, accuracy, and fluency (CAF) in L2 written tasks. Within the cognitive informationprocessing approach of SLA, it was motivated by vague usage and inconsistent effects of planning on L2 performance. First, 459 undergraduate students performed two written narrative tasks. The first task was a proficiency task and the second, main one had three different planning conditions: no planning, pre-task planning, and online planning. The participants were divided into intermediate and advanced levels by the proficiency task results. After the data of 38 subjects were excluded through screening by the main task, writings of the final 421 participants were then evaluated in terms of CAF. Findings revealed that the intermediate learners’ planning benefits CAF enhancement, but the advanced learners’ planning is less beneficial, which indicates that planning is a compensating strategy for L2 learners’ limited attentional resources. Specifically, no planning led to greater accuracy, pre-task planning enhanced fluency, and online planning improved greater syntactic complexity. The results of this research will hopefully aid to understand how L2 performance is controlled by the attentional manipulation of planning, depending on L2 proficiency. The study also suggests that online planning in L2 written tasks might be empirically different compared to that in L2 spoken tasks.