Learning power and language expressiveness

The topic of the present work is to study the relationship between the power of the learning algorithms on the one hand, and the expressive power of the logical language which is used to represent the problems to be learned on the other hand. The central question is whether enriching the language results in more learning power. In order to make the question relevant and nontrivial, it is required that both texts (sequences of data) and hypotheses (guesses) be translatable from the “rich” language into the “poor” one. The issue is considered for several logical languages suitable to describe structures whose domain is the set of natural numbers. It is shown that enriching the language does not give any advantage for those languages which define a monadic second-order language being decidable in the following sense: there is a fixed interpretation in the structure of natural numbers such that the set of sentences of this extended language true in that structure is decidable. But enriching the original language even by only one constant gives an advantage if this language contains a binary function symbol (which will be interpreted as addition). Furthermore, it is shown that behaviourally correct learning has exactly the same power as learning in the limit for those languages which define a monadic second-order language with the property given above, but has more power in case of languages containing a binary function symbol. Adding the natural requirement that the set of all structures to be learned is recursively enumerable, it is shown that it pays o6 to enrich the language of arithmetics for both finite learning and learning in the limit, but it does not pay off to enrich the language for behaviourally correct learning.

Automatic spoken language identification utilizing acoustic and phonetic speech information

Automatic spoken Language Identi¯cation (LID) is the process of identifying the language spoken within an utterance. The challenge that this task presents is that no prior information is available indicating the content of the utterance or the identity of the speaker. The trend of globalization and the pervasive popularity of the Internet will amplify the need for the capabilities spoken language identi¯ca- tion systems provide. A prominent application arises in call centers dealing with speakers speaking di®erent languages. Another important application is to index or search huge speech data archives and corpora that contain multiple languages. The aim of this research is to develop techniques targeted at producing a fast and more accurate automatic spoken LID system compared to the previous National Institute of Standards and Technology (NIST) Language Recognition Evaluation. Acoustic and phonetic speech information are targeted as the most suitable fea- tures for representing the characteristics of a language. To model the acoustic speech features a Gaussian Mixture Model based approach is employed. Pho- netic speech information is extracted using existing speech recognition technol- ogy. Various techniques to improve LID accuracy are also studied. One approach examined is the employment of Vocal Tract Length Normalization to reduce the speech variation caused by di®erent speakers. A linear data fusion technique is adopted to combine the various aspects of information extracted from speech. As a result of this research, a LID system was implemented and presented for evaluation in the 2003 Language Recognition Evaluation conducted by the NIST.

A programming language for software components

Component software has many benefits, most notably increased software re-use; however, the component software process places heavy burdens on programming language technology, which modern object-oriented programming languages do not address. In particular, software components require specifications that are both sufficiently expressive and sufficiently abstract, and, where possible, these specifications should be checked formally by the programming language. This dissertation presents a programming language called Mentok that provides two novel programming language features enabling improved specification of stateful component roles. Negotiable interfaces are interface types extended with protocols, and allow specification of changing method availability, including some patterns of out-calls and re-entrance. Type layers are extensions to module signatures that allow specification of abstract control flow constraints through the interfaces of a component-based application. Development of Mentok's unique language features included creation of MentokC, the Mentok compiler, and formalization of key properties of Mentok in mini-languages called MentokP and MentokL.

Developing speaking assessment tasks to reflect the 'social turn' in language testing

Interactional competence has emerged as a focal point for language testing researchers in recent years. In spoken communication involving two or more interlocutors, the co-construction of discourse is central to successful interaction. The acknowledgement of co-construction has led to concern over the impact of the interlocutor and the separability of performances in speaking tests involving interaction. The purpose of this article is to review recent studies of direct relevance to the construct of interactional competence and its operationalisation by raters in the context of second language speaking tests. The review begins by tracing the emergence of interaction as a criterion in speaking tests from a theoretical perspective, and then focuses on research salient to interactional effectiveness that has been carried out in the context of language testing interviews and group and paired speaking tests.

High-challenge teaching for senior English as an Additional Language (EAL) learners in times of change

This paper will present a brief overview of the recent shifts within English and EAL/D (English as an additional language/dialect) curriculum documents and their focus on critical literacy, using the Queensland context as a case in point. The English syllabus landscape in Queensland has continued to morph in recent years. From 2002 to 2009, teachers of senior English and English as an Additional Language (EAL/D) have witnessed no less than four separate syllabus documents that impact on their daily work. The Australian Curriculum, when finally implemented, will also require teachers to navigate and grapple with its particular obligations and affordances. The combined effect of the shifts and tensions between recent policy documents has led to confusion about exactly how to cater for EAL/D learners in mainstream English. We discuss the possible effects of this on teachers as the agents of policy implementation and argue that in spite of such contradictions, EAL/D teachers can productively use syllabus frameworks to craft pedagogy to cater for their EAL/D learners’ language and literacy needs. Following this, we present aspects of the teaching practice of four teachers of senior EAL/D, who provide intellectually-engaging, critical literacy pedagogy that takes into account the language proficiency level of their learners, within the required curriculum. Such practice provides teachers with valuable pedagogic possibilities to meet EAL/D learners’ needs within continually varying policy terrain.

English language study abroad program : an investigation of Hong Kong pre-service teachers’ experiences of a language immersion program

There has been minimal research focused on short-term study abroad language immersion programs, in particular, with home-stay families. The importance of authentic intercultural experience is increasingly clear and was acknowledged as central to the process of language learning (Liddicoat, 2004). In Hong Kong, education programs for pre-service language teachers have significantly emphasised language and intercultural training through short-term study abroad, and these short overseas language immersion courses have become a compulsory component for teacher training (Bodycott & Crew, 2001) in the last decade. This study aims to investigate eight Hong Kong pre-service teachers’ and their home-stay families’ experiences of a short-term (two months) language immersion program in Australia. The focus is on listening to commentaries concerning the development of communicative competence, intercultural competence and professional growth during the out-of-class study abroad experience. The conceptual framework adopted in this study views language and intercultural learning from social constructivist perspectives. Central to this framing is the notion that the internalisation of higher mental functions involves the transfer from the inter-psychological to the intra-psychological plane, that is, a progression process from the socially supported to individually controlled performance. From this perspective, language serves as a way to communicate about, and in relation to, actions and experience. Three research questions were addressed and studied through qualitative methodology. 1. How do the pre-service teachers and their home-stay families perceive the out-of-class component of the program in terms of opportunities for the development of language proficiency and communicative competence? 2. How do the pre-service teachers and their home-stay families perceive the out-of-class component of the program in terms of the development of intercultural competence? 3. How do the pre-service teachers and home-stay families perceive the outof- class component of the program in terms of teachers’ professional growth? Data were generated from multiple data collection methods and analysed through thematic analysis from both a “bottom up” and “top down” approach. The study showed that the pre-service teachers perceived that the immersion program influenced, to varying degrees, their language proficiency, communication and intercultural awareness, as well as their self-awareness and professional growth. These pre-service teachers believed that effective language learning centres on active engagement in the target language community. A mismatch between the views and evaluations of the two groups – the pre-service teachers and the home-stay family members – provides some evidence of misalignments in terms of expectations and perceptions of each other’s roles and responsibilities. The study has highlighted challenges encountered, and provided suggestions for ways of meeting these challenges. The inclusion in the study of the home-stay families’ perceptions and commentaries provided insights, which can inform program development. There is clearly further work to be done in terms of predeparture orientation and preparation, not only for the main participants themselves, the students, but also for the host families.

Cracking the language code : NAPLAN numeracy tests in years 7 and 9

Focusing on the use of language is a crucial strategy in good mathematics teaching and a teacher’s guidance can assist students to master the language of mathematics. This article discusses the statements with reference to recent year 7 and 9 NAPLAN numeracy tests. It draws the readers’ attention to the complexities of language in the field of mathematics. Although this article refers to NAPLAN numeracy tests it also offers advice about good teaching practice.

Whole-proteome phylogeny of large dsDNA viruses and parvoviruses through a composition vector method related to dynamical language model

Background The vast sequence divergence among different virus groups has presented a great challenge to alignment-based analysis of virus phylogeny. Due to the problems caused by the uncertainty in alignment, existing tools for phylogenetic analysis based on multiple alignment could not be directly applied to the whole-genome comparison and phylogenomic studies of viruses. There has been a growing interest in alignment-free methods for phylogenetic analysis using complete genome data. Among the alignment-free methods, a dynamical language (DL) method proposed by our group has successfully been applied to the phylogenetic analysis of bacteria and chloroplast genomes. Results In this paper, the DL method is used to analyze the whole-proteome phylogeny of 124 large dsDNA viruses and 30 parvoviruses, two data sets with large difference in genome size. The trees from our analyses are in good agreement to the latest classification of large dsDNA viruses and parvoviruses by the International Committee on Taxonomy of Viruses (ICTV). Conclusions The present method provides a new way for recovering the phylogeny of large dsDNA viruses and parvoviruses, and also some insights on the affiliation of a number of unclassified viruses. In comparison, some alignment-free methods such as the CV Tree method can be used for recovering the phylogeny of large dsDNA viruses, but they are not suitable for resolving the phylogeny of parvoviruses with a much smaller genome size.