A new decision to take for cost-sensitive Naïve Bayes classifiers

Practical classification problems often involve some kind of trade-off between the decisions a classifier may take. Indeed, it may be the case that decisions are not equally good or costly; therefore, it is important for the classifier to be able to predict the risk associated with each classification decision. Bayesian decision theory is a fundamental statistical approach to the problem of pattern classification. The objective is to quantify the trade-off between various classification decisions using probability and the costs that accompany such decisions. Within this framework, a loss function measures the rates of the costs and the risk in taking one decision over another.     

The role of word recognition,oral reading fluency and listening comprehension in the simple view of reading: a study in an intermediate depth orthography

Empirical research has provided evidence for the simple view of reading across a variety of orthographies, but the role of oral reading fluency in the model is unclear. Moreover, the relative weight of listening comprehension, oral reading fluency and word recognition in reading comprehension seems to vary across orthographies and schooling years. This study aims to examine the direct effects of these three variables on reading comprehension and to test for the existence of indirect effects of word recognition and listening comprehension on reading comprehension via oral reading fluency in European Portuguese, an orthography of intermediate depth. A sample of 264 students was assessed at the end of grades 2 and 4. Structural equation modeling analyses indicated that listening comprehension, word recognition and oral reading fluency predicted reading comprehension in both grade 2 and grade 4. Moreover, the three variables measured in grade 2 predicted later reading comprehension in grade 4. Listening comprehension was always the strongest predictor. Oral reading fluency mediated the relationship between word recognition and reading comprehension, but it was not a mediator variable in the relationship between listening comprehension and reading comprehension. These findings indicate that, similarly to what has been found for other orthographies, the simple view of reading is a valid framework to account for reading comprehension variability in European Portuguese and that interventions to increase reading comprehension levels should focus on word recognition, fluency, and, especially, listening comprehension.     

Meta‐Analytic Methodology and Inferences About the Efficacy of Formative Assessment

In a recent article published in EM:IP, Kingston and Nash report on the results of a meta‐analysis on the efficacy of formative assessment. They conclude that the average effect of formative assessment on student achievement is about .20 SD units. This would seem to dispel the myth that effects between .40 and .70 can be attributed to formative assessment. They also find that there is considerable variability in effect sizes across studies, and that only the content area in which the treatment is situated explains a significant proportion of study variability. However, there are issues in the meta‐analytic methodology employed by the authors that make their findings somewhat equivocal. This commentary focuses on four methodological concerns about the Kingston and Nash meta‐analysis: (1) the approach taken to select studies for inclusion, (2) the application of study inclusion criteria, (3) the extent to which the effect sizes being combined are biased, and (4) the relationship between effect size magnitude and characteristics of outcome measures. After examining these issues in the context of the Kingston and Nash review, it appears that considerable uncertainty remains about the effect that formative assessment practices have on student achievement.     

Why is it so difficult? Misconceptions about Eastern European education in transition

Eastern European educational systems today face many problems, frequently described in recent publications. This paper discusses several misconceptions both in Western and in Eastern countries, which render more difficult the change process. These concern the inherited situation, reforms underway, power relationships, decentralisation, the roles of tradition and Western assistance, curriculum, financial and statistical data and the relationship between education and society.

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Zusammenfassung Die osteuropäischen Bildungssysteme sehen sich heute vielen Problemen gegenüber, die häufig Thema von kürzlich erschienenen Publikationen sind. In diesem Artikel werden verschiedene sowohl im Westen als auch im Osten bestehende Mißverhältnisse angesprochen, durch die der Änderungsprozeß erschwert wird. Dazu gehören ererbte Zustände, im Gange befindliche Reformen, Machtverhältnisse, Dezentralisierung, die Rolle von Traditionen sowie von Hilfsleistungen aus dem Westen, das Curriculum, finanzielle und statistische Daten sowie die Beziehung zwischen Bildung und Gesellschaft.

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Résumé Les systèmes d'éducation de l'Europe orientale font face aujourd'hui à maints problèmes fréquemment présentés dans de récentes publications. Cet article traite de plusieurs méconceptions perçues à la fois dans les pays de l'Ouest que dans ceux de l'Est qui rendent plus difficile le processus de changement. Elles concernent la situation héritée, les réformes en cours, les relations de pouvoir, la décentralisation, les rôles de la tradition ainsi que de l'aide occidentale, le curriculum, les données financières et statistiques, et la relation entre l'éducation et la société.

     

Cross-national comparisons of developmental dyslexia in Italy and the United States

This study was designed to examine whether the phonetic regularity of a language can significantly influence the prevalence and pattern of developmental dyslexia. Demographically matched samples of fifth-grade children in Italy (N = 448) and the United States (N = 1,278) were evaluated to identify children with specific reading disabilities. Reading disabled children with average intelligence were compared to normal controls on a series of neuropsychological tests to evaluate specific cognitive deficits associated with reading disorders in each country. The findings suggested that (a) dyslexia is more prevalent in the United States than in Italy, (b) reading disabilities are strongly associated with disorders of verbal processing in both countries, although some American dyslexics also show visual-motor deficits, and (c) there is a greater dissociation between reading comprehension and decoding in Italian than in English.     

Microscopy Images as Interactive Tools in Cell Modeling and Cell Biology Education

The advent of genomics, proteomics, and microarray technology has brought much excitement to science, both in teaching and in learning. The public is eager to know about the processes of life. In the present context of the explosive growth of scientific information, a major challenge of modern cell biology is to popularize basic concepts of structures and functions of living cells, to introduce people to the scientific method, to stimulate inquiry, and to analyze and synthesize concepts and paradigms. In this essay we present our experience in mixing science and education in Brazil. For two decades we have developed activities for the science education of teachers and undergraduate students, using microscopy images generated by our work as cell biologists. We describe open-air outreach education activities, games, cell modeling, and other practical and innovative activities presented in public squares and favelas. Especially in developing countries, science education is important, since it may lead to an improvement in quality of life while advancing understanding of traditional scientific ideas. We show that teaching and research can be mutually beneficial rather than competing pursuits in advancing these goals.     

Towards mapping library and information science

In an earlier study by the authors, full-text analysis and traditional bibliometric methods were combined to map research papers published in the journal Scientometrics. The main objective was to develop appropriate techniques of full-text analysis and to improve the efficiency of the individual methods in the mapping of science. The number of papers was, however, rather limited. In the present study, we extend the quantitative linguistic part of the previous studies to a set of five journals representing the field of Library and Information Science (LIS). Almost 1000 articles and notes published in the period 2002–2004 have been selected for this exercise. The optimum solution for clustering LIS is found for six clusters. The combination of different mapping techniques, applied to the full text of scientific publications, results in a characteristic tripod pattern. Besides two clusters in bibliometrics, one cluster in information retrieval and one containing general issues, webometrics and patent studies are identified as small but emerging clusters within LIS. The study is concluded with the analysis of cluster representations by the selected journals.     

Facebook class groups of high school students: their role in establishing social dynamics and learning experiences

The study’s main aim was to explore the role of Facebook class groups, created and managed by high-school students, in facilitating social dynamics and learning experiences. Fourteen Facebook class groups were observed online and students were subsequently questioned through focus-group interviews. Our findings show that Facebook class groups can promote both bonding and learning. Bonding can be enhanced because Facebook class groups foster a sense of solidarity and unity among students. Also, Facebook can stimulate (social) learning because students gain more insights in the subject matter and are challenged to carry out an evaluation of their own study methods and progress. Therefore, drawing on the theories of seamless learning and affinity spaces, we conclude that Facebook class groups are important for social affiliation and effective learning.