Authorship attribution based on a probabilistic topic model

This paper describes, evaluates and compares the use of Latent Dirichlet allocation (LDA) as an approach to authorship attribution. Based on this generative probabilistic topic model, we can model each document as a mixture of topic distributions with each topic specifying a distribution over words. Based on author profiles (aggregation of all texts written by the same writer) we suggest computing the distance with a disputed text to determine its possible writer. This distance is based on the difference between the two topic distributions. To evaluate different attribution schemes, we carried out an experiment based on 5408 newspaper articles (Glasgow Herald) written by 20 distinct authors. To complement this experiment, we used 4326 articles extracted from the Italian newspaper La Stampa and written by 20 journalists. This research demonstrates that the LDA-based classification scheme tends to outperform the Delta rule, and the χ² distance, two classical approaches in authorship attribution based on a restricted number of terms. Compared to the Kullback–Leibler divergence, the LDA-based scheme can provide better effectiveness when considering a larger number of terms.     

Searching strategies for the Hungarian language

This paper reports on the underlying IR problems encountered when dealing with the complex morphology and compound constructions found in the Hungarian language. It describes evaluations carried out on two general stemming strategies for this language, and also demonstrates that a light stemming approach could be quite effective. Based on searches done on the CLEF test collection, we find that a more aggressive suffix-stripping approach may produce better MAP. When compared to an IR scheme without stemming or one based on only a light stemmer, we find the differences to be statistically significant. When compared with probabilistic, vector-space and language models, we find that the Okapi model results in the best retrieval effectiveness. The resulting MAP is found to be about 35% better than the classical tf idf approach, particularly for very short requests. Finally, we demonstrate that applying an automatic decompounding procedure for both queries and documents significantly improves IR performance (+10%), compared to word-based indexing strategies.     

A true original

Abstract

This study analyzes Japanese and Korean ethno-national (minzoku-kokumin) education in postwar Japan. During a period of political unrest in Japan (1945–1955), some of the Korean residents and Japanese worked together to overcome the culture of Imperial Japan and its assimilative education. They also regarded themselves as people colonized by the United States, and pursued a political-cultural movement for their liberation and independence from American imperialism. The Koreans in Japan rejected compulsory education in the Japanese language. As a result, since 1956, Korean schools (Chōsengakkō), funded and supported by North Korea, were founded all across Japan. Their ethno-national education was in fact incorporated into North Korean politics, and has been considered in many studies as having overcome Japanese assimilation and ethnic inequalities. Such a view was a result of many academic Zainichi Korean studies that come from an “insider's perspective” to criticize Japanese colonialism and discrimination. In order to go beyond this insider's view, I focus on the political alliance between Zainichi Koreans and the Japanese people in their pursuit of ethno-national education. Since 2010, the Japanese state funding for Korean schools has become a major controversy in Japan. By tracing the historical background, this article intends to explain why this political issue has arisen. The ultimate purpose of this article is to suggest an ethical perspective to resolve the current political conflict regarding Korean schools in Japan.     

Toward an understanding of academic self‐concept in distance education

Abstract

Academic self‐concept has been demonstrated to influence student success in distance education. The purpose of this study was to examine the nature of academic self‐concept in distance education and to determine its enhancers and detractors. It was determined that this construct is dynamic and multi‐faceted: the process of both learning as an adult and learning at a distance, as well as the content studied, influences academic self‐concept. Implications for both practice and further research are discussed.     

European Dissertation Summaries

Over the past decade, Donald Schön's conceptualization of professional practice as reflection‐in‐action has gained wide currency. This paper reports on a seminar, based on Schon's ideas, to assist elementary teachers in making Science a more significant part of their instructional programmes. A detailed analysis of the efforts of two of the experienced teachers involved points to problems related to: (i) the efficacy of reflection‐on‐action in facilitating reflecting‐in‐action; (ii) disjunctions between conceptual and action components of teachers' frames; and (iii) the role of substantive teacher intervention in assisting children in learning to use non‐common‐sense ways of knowing such as Science.     

Searching strategies for the Bulgarian language

This paper reports on the underlying IR problems encountered when indexing and searching with the Bulgarian language. For this language we propose a general light stemmer and demonstrate that it can be quite effective, producing significantly better MAP (around + 34%) than an approach not applying stemming. We implement the GL2 model derived from the Divergence from Randomness paradigm and find its retrieval effectiveness better than other probabilistic, vector-space and language models. The resulting MAP is found to be about 50% better than the classical tf idf approach. Moreover, increasing the query size enhances the MAP by around 10% (from T to TD). In order to compare the retrieval effectiveness of our suggested stopword list and the light stemmer developed for the Bulgarian language, we conduct a set of experiments on another stopword list and also a more complex and aggressive stemmer. Results tend to indicate that there is no statistically significant difference between these variants and our suggested approach. This paper evaluates other indexing strategies such as 4-gram indexing and indexing based on the automatic decompounding of compound words. Finally, we analyze certain queries to discover why we obtained poor results, when indexing Bulgarian documents using the suggested word-based approach.     

Influence of a stressing constraint on stiffness and damping functions of a ski simulator's platform motion

The aim of this study was to assess the effect of stress on a previously acquired motor coordination. Following a longitudinal learning experiment, four participants performed oscillations on a ski simulator, either in normal or stressful conditions. The results showed that the amplitude of the oscillations decreased under stress, but no significant effect was seen regarding coordination, suggesting the strong resistance to stress of overlearned behaviour. Nevertheless, for one participant, a transient regression towards a former stage of learning was observed. This result was consistent with the regression hypothesis formulated by Fuchs (1962).     

The coach-athlete relationship: a motivational model

The aim of this paper is to present a motivational model of the coach-athlete relationship that describes how coaches may influence athletes' motivation. In line with cognitive evaluation theory (Deci and Ryan, 1980, 1985) and the hierarchical model of intrinsic and extrinsic motivation (Vallerand, 1997, 2000), a motivational sequence is proposed where coaches' personal orientation towards coaching, the context within which they operate, and their perceptions of their athletes' behaviour and motivation influence coaches' behaviours. Also, coaches' behaviours in the form of autonomy-supportive behaviours, provision of structure and involvement have a beneficial impact on athletes' needs for autonomy, competence and relatedness, which, in turn, nurture athletes' intrinsic motivation and self-determined types of extrinsic motivation. Here, we first review coaches' autonomy-supportive behaviours. We then describe the psychological processes through which coaching behaviours have a positive influence on athletes' intrinsic and self-determined extrinsic motivation. Finally, we identify social and personality processes that determine coaching behaviours.