Scoring validity of the Aptis Speaking test: investigating fluency across tasks and levels of proficiency

Second language oral fluency has long been considered as an important construct in communicative language ability (e.g. de Jong et al, 2012) and many speaking tests are designed to measure fluency aspect(s) of candidates’ language (e.g. IELTS, TOEFL iBT, PTE Academic). Current research in second language acquisition suggests that a number of measures of speed, breakdown and repair fluency can reliably assess fluency and predict proficiency. However, there is little research evidence to indicate which measures best characterise fluency at each level of proficiency, and which can consistently distinguish one proficiency level from the next. The study reported in this report is an attempt to help answer these questions. This study investigated fluency constructs across four different levels of proficiency (A2-C1) and four different semi-direct speaking test tasks performed by 32 candidates taking the Aptis Speaking test. Using PRAAT (Boersma & Weenik, 2013), we analysed 120 task performances on different aspects of utterance fluency including speed, breakdown and repair measures across different tasks and levels of proficiency. The results suggest that speed measures consistently distinguish fluency across different levels of proficiency, and many of the breakdown measures differentiate between lower (A2, B1) and higher levels (B2 and C1). The varied use of repair measures at different proficiency levels and tasks suggest that a more complex process is at play. The non-significant differences between most of fluency measures in the four tasks suggest that fluency is not affected by task type in the Aptis Speaking test. The implications of the findings are discussed in relation to the Aptis Speaking test fluency rating scales and rater training materials

A 3D immersive discrete event simulator for enabling prototyping of factory layouts

There is an increasing need to eliminate wasted time and money during factory layout design and subsequent construction. It is presently difficult for engineers to foresee if a certain layout is optimal for work and material flows. By exploiting modelling, simulation and visualisation techniques, this paper presents a tool concept called immersive WITNESS that combines the modelling strengths of Discrete Event Simulation (DES) with the 3D visualisation strengths of recent 3D low cost gaming technology to enable decision makers make informed design choices for future factories layouts. The tool enables engineers to receive immediate feedback on their design choices. Our results show that this tool has the potential to reduce rework as well as the associated costs of making physical prototypes

Product forms for availability

This paper shows and illustrates that product form expressions for the steady state distribution, as known for queueing networks, can also be extended to a class of availability models. This class allows breakdown and repair rates from one component to depend on the status of other components. Common resource capacities and repair priorities, for example, are included. Conditions for the models to have a product form are stated explicitly. This product form is shown to be insensitive to the distributions of the underlying random variables, i.e. to depend only on their means. Further it is briefly indicated how queueing for repair can be incorporated. Novel product form examples are presented of a simple series/parallel configuration, a fault tolerant database system and a multi-stage interconnection network

Analysis of MAP/PH/1 Queueing Model with Breakdown, Instantaneous Feedback and Server Vacation

In this article, we analyze a single server queueing model with feedback, a single vacation under Bernoulli schedule, breakdown and repair. The arriving customers follow the Markovian Arrival Process (MAP) and service follow the phase-type distribution. When the server returns from vacation, if there is no one present in the system, the server will wait until the customer’s arrival. When the service completion epoch if the customer is not satisfied then that customer will get the service immediately. Under the steady-state probability vector that the total number of customers are present in the system is probed by the Matrix-analytic method. In our model, the stability condition, some system performance measures are discussed and we have examined the analysis of the busy period. Numerical results and some graphical representation are discussed for the proposed model

The Influence of working memory on L2 oral fluency: an exploratory study

Màster de Lingüística Aplicada i Adquisició de Llengües en Contextos Multilingües, Departament de Filologia Anglesa i Alemanya, Universitat de Barcelona, Any: 2012, Supervisor: Dr. Roger GilabertThe goal of this exploratory study is to investigate the effect of working memory capacity on L2 oral fluency in 79 learners of English as a foreign language. Three tasks were used as measures of working memory (the reading span task, letter span task and an attention-switching task). Twelve measures of fluency were used spanning across speed, breakdown and repair fluency. Positive correlations were found with measures of repair fluency, specifically morphosyntactic, differency, and other repairs whereas negative correlations were found for lexical repairs. When participants were divided into groups based on proficiency, potential relationships were found between working memory and speed/breakdown fluency suggesting the possible existence of proficiency thresholds affecting the relationship between working memory and fluency. The results are discussed in light of previous research and De Bot’s (1992) model of L2 speech production

Predicting L2 fluency from L1 fluency behaviour: the case of L1 Turkish and L2 English speakers

The article reports on the findings of a study investigating the relationship between first language (L1) and second language (L2) fluency behaviour. Drawing on data collected from Turkish learners of English, the study also addresses the question of whether proficiency level mediates the relationship, if any. The data were coded for a range of breakdown, repair, speed and composite measures. Language proficiency was measured by means of two tests: Oxford Placement Test and an Elicited Imitation Task. The results show that some breakdown and repair measures were positively correlated in L1 and L2, but no correlations were observed for articulation rate and speech rate. The relationships were not mediated by proficiency level. Regression analyses show that a number of models predicted L2 fluency. L1 fluency contributed significantly to models predicting pausing behaviour; EIT scores predicted L2 speech rate; and L1 fluency and OPT scores predicted L2 reformulation and end-clause pauses. The important implications of the findings for fluency research and second language pedagogy are discussed