Genetic and environmental influences on rapid naming and reading ability: A twin study

The present study assesses the genetic and environmental etiologies of reading, rapid naming (RN), and their covariation by fitting multivariate structural equation models to data from 587 twin pairs in which at least one member of the pair exhibited reading difficulties (low-range) and from 360 control (normal-range) twin pairs who were tested in the Colorado Learning Disabilities Research Center. Results from a bivariate phenotypic analysis with two hypothesized latent factors, READ and RN, indicated that the correlation between reading and rapid naming performance for the low-range sample was significantly higher than that of the normal-range sample. When this model was partitioned to include estimates of genetic, shared environmental, and nonshared environmental influences, resulting heritability estimates did not differ significantly for the low-range and normal-range samples for either READ or RN. However, similar to the phenotypic correlation, the genetic correlation between the READ and RN latent factors could not be equated for the two groups. Thus, the etiology of the relationship between reading performance and rapid naming may differ for children with reading difficulties and normally-achieving readers. Moreover, these results support previous findings that the best predictors of reading skills may differ for samples of children with normal reading levels and those with reading difficulties.     

Empirical versus subjective procedures for identifying gender differences in science test items

When judgmental and statistical procedures are both used to identify potentially gender-biased items in a test, to what extent do the results agree? In this study, both procedures were used to evaluate the items in a statewide, 78-item, multiple-choice test of science knowledge. Only one item was flagged by the sensitivity reviewers as being potentially biased, but this item was not flagged by the statistical procedure. None of the nine items flagged by the Mantel-Haenszel procedure were flagged by the sensitivity reviewers. Eight of the nine statistically flagged items were differentially easier for males. Four of these eight measured the same category of objectives. The authors conclude that both judgmental and statistical procedures provide useful information and that both should be used in test construction. They caution readers that content-validity issues need to be addressed when making decisions based on the results of either procedure.     

Development of system thinking skills in the context of earth system education

The current study deals with the development of system thinking skills at the junior high school level. The sample population included about 50 eighth‐grade students from two different classes of an urban Israeli junior high school who studied an earth systems‐based curriculum that focused on the hydro cycle. The study addressed the following research questions: (a) Could the students deal with complex systems?; (b) What has influenced the students' ability to deal with system perception?; and (c) What are the relationship among the cognitive components of system thinking? The research combined qualitative and quantitative methods and involved various research tools, which were implemented in order to collect the data concerning the students' knowledge and understanding before, during, and following the learning process. The findings indicated that the development of system thinking in the context of the earth systems consists of several sequential stages arranged in a hierarchical structure. The cognitive skills that are developed in each stage serve as the basis for the development of the next higher‐order thinking skills. The research showed that in spite of the minimal initial system thinking abilities of the students most of them made some meaningful progress in their system thinking skills, and a third of them reached the highest level of system thinking in the context of the hydro cycle. Two main factors were found to be the source of the differential progress of the students: (a) the students' individual cognitive abilities, and (b) their level of involvement in the knowledge integration activities during their inquiry‐based learning both indoors and outdoors. © 2005 Wiley Periodicals, Inc.     

The effects of isolation and handling on reactivity to footshock and tactile dorsal stimulation

The effects of isolation and handling on the reactivity of rats to two tactile stimuli were assessed in two experiments. In the first experiment, reactivity to more intense footshock was increased in rats raised in isolation but was not affected by handling by an experimenter. In the second experiment, increased reactivity to airpuff stimuli presented to the dorsal surface of isolation-reared rats was reduced by handling. The data suggest that the effects of handling on shock-motivated behaviors are not due to altered reactivity to shock and that the effect of housing or handling must be considered in behavioral tests in which reactivity to tactile stimulation might play a role as dependent or independent variables.     

Demand for private supplementary tutoring: conceptual considerations, and socio-economic patterns in Hong Kong

Despite the fact that in some parts of the world private supplementary tutoring is a huge industry with far-reaching economic, social and educational implications, the topic has been neglected by educational researchers. This paper focuses on the nature and determinants of demand for private supplementary tutoring. It first draws on literature from a wide range of countries to identify some conceptual considerations, and then presents data on socio-economic patterns of demand for tutoring in Hong Kong. It highlights the complexity of the topic, and calls for further detailed research in multiple settings.     

Helping Prospective Principals Understand the Mathematics Curriculum: a Singapore experience

Principals should play an important role as curriculum leaders in their schools. To discharge this role effectively, the principals must understand the nature of curriculum not only of the disciplines in which they have been trained, but also of other key disciplines commonly included in the school programme. A way must be found to train the principals to acquire up‐to‐date knowledge of the practices and trends in various subject curricula, so that they can carry out informed discussions with the heads of subject departments to set goals and directions for these programmes. This article focuses on such a programme, called the Diploma in Educational Administration (DEA), which has been developed at the Institute of Education, Singapore to train prospective principals. In particular, the paper shows how local research has been integrated into the training programme to help participants understand the mathematics curriculum.