Minimally supervised induction of morphology through bitexts

textA knowledge of morphology can be useful for many natural language processing systems. Thus, much effort has been expended in developing accurate computational tools for morphology that lemmatize, segment and generate new forms. The most powerful and accurate of these have been manually encoded, such endeavors being without exception expensive and time-consuming. There have been consequently many attempts to reduce this cost in the development of morphological systems through the development of unsupervised or minimally supervised algorithms and learning methods for acquisition of morphology. These efforts have yet to produce a tool that approaches the performance of manually encoded systems. Here, I present a strategy for dealing with morphological clustering and segmentation in a minimally supervised manner but one that will be more linguistically informed than previous unsupervised approaches. That is, this study will attempt to induce clusters of words from an unannotated text that are inflectional variants of each other. Then a set of inflectional suffixes by part-of-speech will be induced from these clusters. This level of detail is made possible by a method known as alignment and transfer (AT), among other names, an approach that uses aligned bitexts to transfer linguistic resources developed for one language–the source language–to another language–the target. This approach has a further advantage in that it allows a reduction in the amount of training data without a significant degradation in performance making it useful in applications targeted at data collected from endangered languages. In the current study, however, I use English as the source and German as the target for ease of evaluation and for certain typlogical properties of German. The two main tasks, that of clustering and segmentation, are approached as sequential tasks with the clustering informing the segmentation to allow for greater accuracy in morphological analysis. While the performance of these methods does not exceed the current roster of unsupervised or minimally supervised approaches to morphology acquisition, it attempts to integrate more learning methods than previous studies. Furthermore, it attempts to learn inflectional morphology as opposed to derivational morphology, which is a crucial distinction in linguistics.Linguistic

On the learnability of E-pattern languages over small alphabets

This paper deals with two well discussed, but largely open problems on E-pattern languages, also known as extended or erasing pattern languages: primarily, the learnability in Gold’s learning model and, secondarily, the decidability of the equivalence. As the main result, we show that the full class of E-pattern languages is not inferrable from positive data if the corresponding terminal alphabet consists of exactly three or of exactly four letters – an insight that remarkably contrasts with the recent positive finding on the learnability of the subclass of terminal-free E-pattern languages for these alphabets. As a side-effect of our reasoning thereon, we reveal some particular example patterns that disprove a conjecture of Ohlebusch and Ukkonen (Theoretical Computer Science 186, 1997) on the decidability of the equivalence of E-pattern languages

A non-learnable class of E-pattern languages

We investigate the inferrability of E-pattern languages (also known as extended or erasing pattern languages) from positive data in Gold’s learning model. As the main result, our analysis yields a negative outcome for the full class of E-pattern languages – and even for the subclass of terminal-free E-pattern languages – if the corresponding terminal alphabet consists of exactly two distinct letters. Furthermore, we present a positive result for a manifest subclass of terminal-free E-pattern languages. We point out that the considered problems are closely related to fundamental questions concerning the nondeterminism of E-pattern languages

Preparing Teacher Candidates to Serve Students From Diverse Backgrounds: Triggering Transformative Learning Through Short-Term Cultural Immersion

This study followed 24 teacher candidates in a short-term cultural immersion field experience designed to help them reflect on their assumptions and perspectives in order to better understand the culturally, ethnically, and linguistically diverse students they will teach. Qualitative methods were informed by a phenomenological research approach to examine candidates’ transformative learning experiences in a cultural immersion context. The findings are discussed within a three-stage framework of transformative learning: triggering experiences, frame of reference examination, and transformative change

The crossroads of English language learners, task-based instruction, and 3D multi-user virtual learning in Second Life

English as a foreign language (EFL) learners' task-based practices in 3D multi-user virtual environments are a dynamic avenue that has attracted research attention in current second language acquisition literature. This study explores EFL adult learners' perceptions and language practices in a 10-session, task-based course in Second Life (SL). A full-blown task-based syllabus that capitalized on meaningful real-life tasks was designed and documented in this study. Employing the grounded theory approach and triangulating multiple qualitative data sources, two core themes emerged: factors that influence SL learning experience and effects of task-based instruction on language learning in SL. SL was evidenced as a viable learning environment due to its conspicuous features, immersive and virtual reality, sense of tele- and co-presence. This study implicates that 1) 3D multimodal resources in SL provide EFL learners with visual and linguistic support and facilitate language teaching and learning; and 2) tasks that draw upon SL features, accommodate learners' cultural/world knowledge, and simulate real-life scenarios, can optimize learners' virtual learning experiences

Sex and Syntax: Subjacency Revisited

Despite the sustained effort of about forty years to analyze Subjacency, to date, there has been no principled account, with the most recent attempts faring not much better than the initial proposals. It is also significant that the seeming arbitrariness of Subjacency has been used to argue that syntax could not have evolved gradually: One does not see why evolution would target a grammar with Subjacency, when its contribution to grammar is not transparent, let alone its contribution to survival. As put in Lightfoot (1991), “Subjacency has many virtues, but … it could not have increased the chances of having fruitful sex”. This article turns the argument around, and proposes that subjecting syntax to a gradualist evolutionary approach can in fact shed light on the existence of Subjacency effects. It thereby offers a reconstruction of how communicative benefits may have been involved in shaping the formal design of language