Research, design, implementation, and evaluation of CALL materials needs to be based on sound SLA theories and research. A research agenda of CALL issues needs to be identified and investigated by means of suitable methodology. I propose that a Sociocultural approach to language learning provides a useful theoretical framework to investigate the process of collaborative activity in computer-mediated tasks. Following a brief overview of Sociocultural theory in relation to its claims about the usefulness of collaborative activity in the language classroom, I provide an account of issues to be addressed in task design. Finally, I exemplify from a study currently taking place how collaborative activity in computer-mediated tasks can be empirically studied, and I outline some of the methodological considerations underpinning such research work.

Previous research has underscored the role of negotiation in providing appropriate conditions for second language acquisition. Varonis and Gass (1985b), in a study of English as a Second Language (ESL), found greater amount of negotiation in non-native–non-native interaction than in native-non–native interaction. Given the increased interest in computer mediated communication and in its applications to language learning, this investigation explores whether those results are obtained when using an electronic written medium. This study compared the negotiations generated by dyads of non-native speakers (NNS–NNS), native speakers (NS–NS), and non-native and native speakers (NNS–NS), in the oral and written modes. The results revealed that the NNS–NS group negotiated in the oral mode significantly more than in the written mode; this group also negotiated significantly more than the other two groups in the oral mode. Learners' shared social and linguistic background seemed to have facilitated the comprehension of input. Conversely, lack of familiarity with native speaker's pronunciation seemed to have caused more breakdowns in the oral conversations of the mixed dyads. Though the results of this study suggest that negotiation is not the main resource to obtain modified input in a foreign language context, other learning strategies that may be beneficial in the language learning process were at use in learner-learner interaction.

This article will start with the situation at the Open University, where languages are taught at a distance. Online tuition using an audio-graphic Internet-based conferencing system called Lyceum is one of the ways used to develop students’ communicative skills.

Following Garrett’s call for an integration of research and practice at EUROCALL 1997 (Garrett, 1998) – a call which is still valid today – the present article proposes a conceptual framework which can support the use of conferencing systems such as Lyceum in language learning and teaching. In the first part of the article, I examine several pedagogical theories supporting language learning, that is, second language acquisition and sociocultural theories, and multimodality, and apply them to the practice of audio-graphic computer-mediated communication (CMC) as used at the Open University. I also build on previous research, which, however, is still dominated by written CMC. What Erben stated in 1999 is still true: that audio-graphic technology “remains under-researched and under-theorised.” (Erben, 1999:230). Firstly, I therefore examine studies on written CMC and secondly those that have been conducted on audio-graphic CMC in order to identify the benefits and challenges of these media.

Both the pedagogical theory and previous studies of CMC have informed the design and implementation of online tuition at the Open University. Thus the second part of the article reports on a research project on Lyceum, which took place in 2002. The goal of the project was to evaluate the use of audio-graphic conferencing in practice, and this in turn has instigated both improvements in the software used and in student support as well as further changes to the task design. I present some findings and discuss both the challenges of audio-graphic conferencing that were encountered and the benefits that were identified.

There has been much enthusiasm shown in the literature about Native Speaker-Nonnative Speaker (NS-NNS) e-mail interactions, associating them with increased motivation and participation and reduced anxiety (Beauvois & Eledge, 1996; Leh, 1997; Aitsiselmi, 1999). Recent research has now also begun to link these interactions with increases in L2 proficiency (Floréz-Estrada, 1995; Stockwell & Harrington, 2003). As some studies have suggested that L2 learners should reach a certain number of e-mail interactions in order for benefits to accrue (Lamy & Goodfellow, 1999; Stockwell & Harrington, 2003), researchers have started to turn their attention towards what factors play a role in helping to facilitate longer interactions. One factor that appears to be important in sustaining longer conversation sequences is the topics discussed during the interactions (Stockwell & Levy, 2001). While Lamy & Goodfellow (1999) investigated the topic threads during on-line discussions with multiple participants, threads in NS-NNS paired interactions through e-mail remain largely unexplored. Thus, in this study, 48 learners of Japanese involved in e-mail interactions with native speakers were investigated to determine what features of topic threads contributed to sustaining interactions. The end-of-thread messages (i.e., those messages which were the last message in a conversation thread) were examined in terms of whether or not a reply was invited, and those messages for which a reply was invited were further analysed to determine why a reply was not received. The paper concludes with suggestions for how conversation threads may be sustained, and some directions for future research.

EUROCALL continued to operate from the C&IT Centre of the Language Institute at the University of Hull, with June Thompson as Secretary, Graham Chesters as Treasurer and Julie Venner as Membership Secretary, assisted by Fred Riley and Janet Bartle. However, due to impending changes in the staffing arrangements at Hull, steps are being taken to identify an appropriate venue for the EUROCALL headquarters from September 2003.

In this article, we derive closed-form expressions of the large deviations local rate function in terms of the arrival and service parameters for the zero path in exponential queueing networks corresponding to a coupled-processors system.

We explore visit-order policies in nonsymmetric polling systems with switch-in and switch-out times, where service is in batches of unlimited size. We concentrate on so-called “Hamiltonian tour” policies in which, in order to give a fair treatment to the various users, the server attends every nonempty queue exactly once during each round of visits (cycle). The server dynamically generates a new visit schedule at the start of each round, depending on the current state of the system (number of jobs in each queue) and on the various nonhomogeneous system parameters. We consider three service regimes, globally gated, (locally) gated, and exhaustive, and study three different performance measures: (1) minimizing the expected weighted sum of all sojourn times of jobs within a cycle; (2) minimizing the expected length of the next cycle, and (3) maximizing the expected weighted throughput in a cycle. For each combination of performance measure and service regime, we derive characteristics of the optimal Hamiltonian tour. Some of the resulting optimal policies are shown to be elegant index-type rules. Others are the solutions of deterministic NP-hard problems. Special cases are reduced to assignment problems with specific cost matrices. The index-type rules can further be used to construct fixed-order, cyclic-type polling tables in cases where dynamic control is not applicable.

We studied several group testing models with and without processing times. The objective was to choose an optimal group size for pooled screening of a contaminated population so as to collect a prespecified number of good items from it with minimum testing expenditures. The tested groups that were found to be contaminated were used as a new sampling population in later stages of the procedures. Since testing may be time-consuming, we also considered deadlines to be met for the testing process. We derived algorithms and exact results for the underlying distributions, enabling us to find optimal procedures. Several numerical examples are given.

In this article, we analyze the large deviations bounds for the nonergodic face-homogeneous random walk in the positive quadrant. Under some condition the value of the local rate function for the path identically equal to zero is found, and an explicit expression is derived for it. This makes the computation of its value possible for specific stochastic networks. Some numerical examples are given.

Dispersion-type orders are introduced and studied. The new orders can be used to compare the variability of the underlying random variables, among which are the usual dispersive order and the right spread order. Connections among the new orders and other common stochastic orders are examined and investigated. Some closure properties of the new orders under the operation of order statistics, transformations, and mixtures are derived. Finally, several applications of the new orders are given.

This article focuses on simulating fractional Brownian motion (fBm). Despite the availability of several exact simulation methods, attention has been paid to approximate simulation (i.e., the output is approximately fBm), particularly because of possible time savings. In this article, we study the class of approximate methods that are based on the spectral properties of fBm's stationary incremental process, usually called fractional Gaussian noise (fGn). The main contribution is a proof of asymptotical exactness (in a sense that is made precise) of these spectral methods. Moreover, we establish the connection between the spectral simulation approach and a widely used method, originally proposed by Paxson, that lacked a formal mathematical justification. The insights enable us to evaluate the Paxson method in more detail. It is also shown that spectral simulation is related to the fastest known exact method.

For a left-continuous random walk in an orthant with absorbing boundary, the generating function of the transition probabilities is determined by a well-known functional equation. We give a simple probabilistic derivation of this functional equation, which simultaneously proves the hitting point identity and Wald's exponential identity for the absorption time.

We describe and develop a variation on a layered multishift coupler due to Wilson that uses a slice sampling procedure to allow one to obtain potentially common draws from two different distributions. Our main application is coupling sample paths of Markov chains for use in perfect sampling algorithms. The coupler is based on slicing density functions and we describe a “folding” mechanism as an attractive alternative to the accept/reject step commonly used in slice sampling algorithms. Applications of the coupler are given to storage models and to auto-gamma distribution sampling.

This paper describes how the use of monadic second-order logic for specifying regular languages can be extended for specifying regular relations, providing a declarative description language for finite state transductions of the sort used in NLP. We discuss issues arising in the integration into an automaton toolkit of an implementation of the conversion from logic formulas to automata. The utility of the logic of regular relations is demonstrated by showing how it can be used to define the family of replacement operators in a way that lends itself to straightforward proofs of correctness.

Finite state methods have been in common use in various areas of natural language processing (NLP) for many years. A series of specialized workshops in this area illustrates this. In 1996, András Kornai organized a very successful workshop entitled Extended Finite State Models of Language. One of the results of that workshop was a special issue of Natural Language Engineering (Volume 2, Number 4). In 1998, Kemal Oflazer organized a workshop called Finite State Methods in Natural Language Processing. A selection of submissions for this workshop were later included in a special issue of Computational Linguistics (Volume 26, Number 1). Inspired by these events, Lauri Karttunen, Kimmo Koskenniemi and Gertjan van Noord took the initiative for a workshop on finite state methods in NLP in Helsinki, as part of the European Summer School in Language, Logic and Information. As a related special event, the 20th anniversary of two-level morphology was celebrated. The appreciation of these events led us to believe that once again it should be possible, with some additional submissions, to compose an interesting special issue of this journal.

The paper investigates the computational complexity of different versions of Optimality Theory (OT). The result of Frank and Satta (1998) is used as a starting point. These authors show that unidirectional optimization can be implemented by finite state techniques if only binary constraints are used. The consequences of (a) taking gradient constraints into account and (b) using bidirectional optimization in the sense of Blutner (2000) are explored. The central result of the paper is that the combination of gradient constraints and bidirectionality leads to a massive increase of computational complexity.

This paper presents the design and implementation of a finite-state syntactic grammar of Basque that has been used with the objective of extracting information about verb subcategorization instances from newspaper texts. After a partial parser has built basic syntactic units such as noun phrases, prepositional phrases, and sentential complements, a finite-state parser performs syntactic disambiguation, determination of clause boundaries and filtering of the results, in order to obtain a verb occurrence together with its associated syntactic components, either complements or adjuncts. The set of occurrences for each verb is then filtered by statistical measures that distinguish arguments from adjuncts.

This paper presents a scheme that allows one to relax the all-or-none nature of two-level constraints in two-level morphology in a controlled manner, so that word forms with violations of some of the two-level constraints can be analyzed and ranked. The problem has been motivated by a recent phenomenon in Turkish with imported words that violate a fundamental assumption of Turkish that pronunciation and orthography have almost a one-to-one correspondence, and by a problem in Basque words with differing amounts of competence errors. We present the formulation of our proposal, and provide details of implementations for both problems using the XRCE Finite State Toolkit.

Hyphenation is the task of identifying potential hyphenation points inwords. In this paper, three finite-state hyphenation methods for Dutch are presented and compared in terms of accuracy and size of the resulting automata.