A behaviour‐genetic analysis of orthographic learning,spelling and decoding

As part of a longitudinal twin study of literacy and language, we conducted a behaviour‐genetic analysis of orthographic learning, spelling and decoding in Grade 2 children (225 identical and 214 fraternal twin pairs) in the United States and Australia. Each variable showed significant genetic and unique environment influences. Multivariate analyses revealed very high genetic correlations among the variables, indicating that the same genes are involved in their aetiology. These genes are partly independent of those contributing to intelligence. A further analysis indicated that the covariation between decoding and orthographic learning is mediated by shared genes rather than by a direct causal path. The authors argue that a learning parameter, most directly assessed by orthographic learning in this study, underlies all three literacy variables. The results are also discussed in relation to Share's self‐teaching hypothesis, which may require modification.     

Genetic and Environmental Etiologies of the Longitudinal Relations Between Prereading Skills and Reading

The present study explored the environmental and genetic etiologies of the longitudinal relations between prereading skills and reading and spelling. Twin pairs (n = 489) were assessed before kindergarten (M = 4.9 years), post‐first grade (M = 7.4 years), and post‐fourth grade (M = 10.4 years). Genetic influences on five prereading skills (print knowledge, rapid naming, phonological awareness, vocabulary, and verbal memory) were primarily responsible for relations with word reading and spelling. However, relations with post‐fourth‐grade reading comprehension were due to both genetic and shared environmental influences. Genetic and shared environmental influences that were common among the prereading variables covaried with reading and spelling, as did genetic influences unique to verbal memory (only post‐fourth‐grade comprehension), print knowledge, and rapid naming.     

The conflict between on-task and off-task actions in the classroom and its consequences for motivation and achievement

The relations between students’ value orientations, decisions in conflicts between on-task and off-task actions in the classroom, and experiences of motivational interference following these conflicts were investigated. It was expected that well-being value orientation was positively linked and achievement value orientation was negatively linked to decision for off-task behavior in such conflicts and that the higher students’ well-being value orientation, the higher their motivational impairment when deciding for the on-task behavior and the lower when deciding for the off-task behavior. For achievement orientation, the relationships were predicted to be reversed. The experience of motivational interference while performing on-task behavior was, in turn, expected to be related to worse grades. Data from 817 students (mean age 13.44) from 35 classrooms were collected using self-report questionnaires and analyzed in a series of hierarchical linear models. Analyses showed the relationships as predicted. All relationships found were comparable to the relationships found for a conflict between school and leisure actions after class. Results point out that even if students resist the off-task temptation in class, the mere possibility of off-task behavior can impair motivation and achievement.     

Facilitating spatial perspective taking through animation: Evidence from an aptitude–treatment-interaction

The present study examined the facilitating function of animations for spatial perspective taking. The task demanded to estimate directions to memorized objects in a spatial scene from an imagined position and orientation within the scene. Static pictures which required imagined reorientation of the self were compared to animations showing the reorientation externally. Individual differences in perspective taking ability were considered. Results showed a large effect in favor of animations for reaction times. An aptitude–treatment-interaction was found for accuracy: The relation between perspective taking ability and accuracy in direction estimation was moderated by type of presentation (static pictures vs. animation). Perspective taking ability played a much stronger role in direction estimation accuracy with static pictures than with animations. It is concluded that focused animations can facilitate perspective taking and thereby compensate for low spatial perspective taking ability.     

Hybrid index maintenance for contiguous inverted lists

Index maintenance strategies employed by dynamic text retrieval systems based on inverted files can be divided into two categories: merge-based and in-place update strategies. Within each category, individual update policies can be distinguished based on whether they store their on-disk posting lists in a contiguous or in a discontiguous fashion. Contiguous inverted lists, in general, lead to higher query performance, by minimizing the disk seek overhead at query time, while discontiguous inverted lists lead to higher update performance, requiring less effort during index maintenance operations. In this paper, we focus on retrieval systems with high query load, where the on-disk posting lists have to be stored in a contiguous fashion at all times. We discuss a combination of re-merge and in-place index update, called Hybrid Immediate Merge. The method performs strictly better than the re-merge baseline policy used in our experiments, as it leads to the same query performance, but substantially better update performance. The actual time savings achievable depend on the size of the text collection being indexed; a larger collection results in greater savings. In our experiments, variations of Hybrid Immediate Merge were able to reduce the total index update overhead by up to 73% compared to the re-merge baseline.

Enhancing the MeSH thesaurus to retrieve French online health resources in a quality-controlled gateway

The amount of health information available on the Internet is considerable. In this context, several health gateways have been developed. Among them, CISMeF (Catalogue and Index of Health Resources in French) was designed to catalogue and index health resources in French. The goal of this article is to describe the various enhancements to the MeSH thesaurus developed by the CISMeF team to adapt this terminology to the broader field of health Internet resources instead of scientific articles for the medline bibliographic database. CISMeF uses two standard tools for organizing information: the MeSH thesaurus and several metadata element sets, in particular the Dublin Core metadata format. The heterogeneity of Internet health resources led the CISMeF team to enhance the MeSH thesaurus with the introduction of two new concepts, respectively, resource types and metaterms. CISMeF resource types are a generalization of the publication types of medline. A resource type describes the nature of the resource and MeSH keyword/qualifier pairs describe the subject of the resource. A metaterm is generally a medical specialty or a biological science, which has semantic links with one or more MeSH keywords, qualifiers and resource types. The CISMeF terminology is exploited for several tasks: resource indexing performed manually, resource categorization performed automatically, visualization and navigation through the concept hierarchies and information retrieval using the Doc'CISMeF search engine. The CISMeF health gateway uses several MeSH thesaurus enhancements to optimize information retrieval, hierarchy navigation and automatic indexing.     

Exploring students’ expectations of learning analytics: A person-centered approach

Education and Information Technologies - In order to successfully implement learning analytics (LA), we need a better understanding of student expectations of such services. Yet, there is still a...