Mathematics classrooms in Japan, Taiwan, and the United States

Observations were conducted in Chinese, Japanese, and American classrooms during mathematics classes. Activities in 20 representative classrooms were observed in each of 2 grades (1 and 5) and in each country. Some observations focused on individual children and others on the teachers. Large cross-cultural differences were found in many variables related to classroom structure and management. These differences paralleled differences in achievement in mathematics among the 3 countries. A number of these variables also were significantly related to average level of mathematics achievement within the American classrooms.     

Language in the Family Domain in Singapore: An Analysis of the 1980 Census Statistics

The 1980 population census of Singapore is the first census that gathered detailed information on languages spoken at home. The data were collected from the 20 per cent sample enumeration, using the following question:     

Probability of error in CPSK systems with intersymbol interference and additive noise

A simple lower bound, an upper bound and a simple approximation to the upper bound on the probability of error for coherent phase-shift-keyed (CPSK) systems operating in the presence of intersymbol interference and additive noise are obtained. The additive noises in the in-phase channel and the quadrature channel are assumed to be independent, and are independent of the signal, but not restricted to be Gaussian. The approximation to the upper bound is four times the lower bound, hence the tightness of these bounds is uniform for all cases. This fact and the simplicity of the bounds make these bounds a useful system design tool. Numerical examples for quaternary and octonary systems are presented and compared to known results.     

A cross-linguistic comparison of phonological awareness and word recognition

Phonological awareness is one of the critical skills in the acquisition of reading in an alphabetic orthography. The development of phonological awareness was compared across Turkish and English-speaking kindergarten and first-grade children (n = 138). The Turkish-speakers were more proficient in both handling of the syllables and deleting final phonemes of words. These patterns were related to the characteristics of the respective spoken languages (such as the saliency of the syllable, familiarity of the nonword patterns, importance of onset or final phoneme deletion, importance of vowel harmony) and the development of phonological awareness was discussed as a function of the characteristics of spoken language, orthography and literacy instruction.     

Classification Consistency and Accuracy With Atypical Score Distributions

The current study aims to evaluate the performance of three non-IRT procedures (i.e., normal approximation, Livingston-Lewis, and compound multinomial) for estimating classification indices when the observed score distribution shows atypical patterns: (a) bimodality, (b) structural (i.e., systematic) bumpiness, or (c) structural zeros (i.e., no frequencies). Under a bimodal distribution, the normal approximation procedure produced substantially large bias. For a distribution with structural bumpiness, the compound multinomial procedure tended to introduce larger bias. Under a distribution with structural zeroes, the relative performance of selected estimation procedures depended on cut score location and the sample-size conditions. In general, the differences in estimation errors among the three procedures were not substantially large.     

Role of Oxidative Stress in Various Stages of Psoriasis

Psoriasis is a chronic inflammatory, proliferative skin disease characterized by pathological skin lesions due to various exogenous and endogenous factors. It is associated with a number of biochemical and immunological disturbances. Recently, it has been suggested that increased reactive oxygen species (ROS) production and compromised function of antioxidant system may be involved in the pathogenesis of this disease. In the present study, 90 psoriasis patients were selected. Disease severity was assessed by psoriasis area severity index score and grouped as mild, moderate and severe (each group consists of 30 subjects) and compared with 30 healthy controls. Serum levels of malondialdehyde, nitric oxide end products and the activities of antioxidant enzymes such as erythrocyte-superoxide dismutase, catalase and total antioxidant status were investigated in these groups/subjects. As compared to controls, we found severitywise significantly increased serum malondialdehyde, nitric oxide end products with decrease in erythrocyte-superoxide dismutase activity, catalase activity and total antioxidant status in patients with psoriasis suggesting worsening of the disease. It seems to be linked with the enhancement of Reactive Oxygen Species production and decreased antioxidant potential in psoriasis.     

Dynamic mental models in learning science: The importance of constructing derivational linkages among models

We present a theory of learning in science based on students deriving conceptual linkages among multiple models which represent physical phenomena at different levels of abstraction. The models vary in the primitive objects and interactions they incorporate and in the reasoning processes that are used in running them. Students derive linkages among models by running a model (embodied in an interactive computer simulation) and reflecting on its emergent behaviors. The emergent properties they identify in turn become the primitive elements of the more abstract, derived model. We describe and illustrate derivational links among three models for basic electricity: a particle model, an aggregate model, and an algebraic model. We then present results of an instructional experiment in which we compared high school students who were exposed to these model derivations with those who were not. In all other respects, both groups of students received identical instruction. The results demonstrate the importance of enabling students to construct derivational linkages among models, both with respect to their understanding of circuit theory and their ability to solve qualitative and quantitative circuit problems. © 1999 John Wiley & Sons, Inc. J Res Sci Teach 36: 806–836, 1999     

Televised violence and viewers’ perceptions of social reality: The Korean case

This study attempts to describe some possible elaborations of the cultivation hypothesis and present relevant evidence from a Korean student sample. Using the postulates and methodology of the cultivation analysis approach to mass communication, this investigation employs a two‐pronged research strategy: message system analysis and cultivation analysis. Message system analysis consisted of one‐week sample of Korean television programs from the three television networks in June 1991. For cultivation analysis, a questionnaire was administered to 1,200 Korean students attending eight junior and senior high schools from five different states in July, 1991. Within the clear limitations of measures, the results suggested that viewers differentially perceive the social reality of different content types. The findings seem to indicate that the degree of cultivation effects is not uniform across different kinds of television programming.