Effect of delay on search decisions in a task-oriented reading environment

The goal of this study was to determine the effect of setting a delay between reading a text and answering comprehension questions on when-to-search and what-to-search decisions in a task-oriented reading environment. Fifty-five eighth-grade students were randomly divided into two groups. One group read one text, answered comprehension questions regarding the text with the text available, and subsequently repeated the procedure with a second text (immediate condition). The other group read both texts first and then answered, with the texts available, the questions for the first text and then for the second text (delayed condition). In both conditions, the readers’ actions during the task were recorded. The results demonstrated that the students in the delayed condition made more search decisions. In addition, moderated mediation analyses indicated that setting a delay had a positive indirect effect on performance via increased searching only for the students with average and high comprehension skills. Moreover, decisions regarding what information to search for depended exclusively on comprehension skill. Instructional implications are discussed.     

一种新的Web Cache技术的研究及实现

提出了一种新的网络共享Cache技术--分组Cache, 通过把所有的共享Cache按其在网络中的位置进行分组, 该方法能够有效地解决多Cache组织查询效率不高和I/O瓶颈等问题. 该技术有以下特点: ①采用分组技术能够有效地降低多Cache间的查询开销; ②组内的Cache数据目录表能够很快确定请求的内容是否在某个Cache中; ③根据网络访问日志确定的分配算法能够较好地平衡各Cache组的负载. 模拟测试证明: 分组Cache技术与其他已有的共享Cache技术相比有较高的效率.     

Arithmetic processing in children with spina bifida: Calculation accuracy, strategy use, and fact retrieval fluency

Three studies compared 98 children with spina bifida myelomeningocele (SBM)-a disorder associated with high rates of math disability and spatial deficits-to 94 typically developing children on multidigit subtraction and cognitive addition tasks. Children with SBM were classified into those with reading decoding and math disability, only math disability, and no reading or math disability. Study 1 showed that visual-spatial errors in multidigit arithmetic were not elevated in children with SBM. In Study 2, deficits in accuracy, speed, and strategy-use in single-digit addition characterized groups with math disability regardless of reading status. Accuracy and speed on single-digit addition was strongly related to performance on multidigit subtraction. A math-level matching design in Study 3 revealed less mastery of math facts by the group with SBM. The results are discussed with reference to cognitive and neuropsychological models of math disability.     

学校与社会环境对学生体育锻炼习惯形成的影响研究

群众体育的发展和国民素质的提高,要求人们有良好的体育锻炼习惯,而它的形成受到众多因素的影响,通过对学校和社会环境两个角度的调查研究,了解和分析了影响学生体育锻炼习惯形成的因素,为学校和社会的体育工作提供参考,使学生更早的养成良好的体育锻炼习惯,终身受益.同时,为新世纪的课改提供依据,使其更能适应我国学生自身发展,更快的实现我国对学生进行终身体育教育的目的.     

Effects of reinforcer delay and variability in a successive-encounters procedure

Pigeons responded in a successive-encounters procedure that consisted of a search period, a choice period, and a handling period. The search period was either a fixed-interval or a mixed-interval schedule presented on the center key of a three-key chamber. Upon completion of the search period, the center key was turned off and the two side keys were lit. A pigeon could either accept a delay followed by food (by pecking the right key) or reject this option and return to the search period (by pecking the left key). During the choice period, a red right key represented the long alternative (a long handling delay followed by food), and a green right key represented the short alternative (a short handling delay followed by food). The experiment consisted of a series of comparisons for which optimal diet theory predicted no changes in preference for the long alternative (because the overall rates of reinforcement were unchanged), whereas the hyperbolic-decay model predicted changes in preference (because the delays to the next possible reinforcer were varied). In all comparisons, the results supported the predictions of the hyperbolic-decay model, which states that the value of a reinforcer is inversely related to the delay between a choice response and reinforcer delivery.     

Differences in memory retrieval: a construct validity investigation

Long-term memory retrieval efficiency was investigated as a potential underlying source of individual and developmental differences in cognitive functioning. Fourth-grade, eighth-grade, and college-aged subjects participated in a task using the Posner letter-matching paradigm. Letter pairs were presented simultaneously under physical-match and name-match instruction conditions. Reaction times were used to estimate parameters of long-term memory retrieval efficiency, basic encoding, decision, and response time, and name and physical output interference. Psychometric tests of verbal and spatial ability were included to assess convergent and discriminant validity of hypothesized relationships between aptitude test performance and basic cognitive processes. Developmental differences were observed in most but not all of the processing variables. Individual difference analyses indicated that less confounded estimates of processing parameters were not systematically related to verbal ability at any age level. Basic encoding and response speed was the most consistent correlate of spatial ability. The results suggest difficulties in previous interpretations of NIPI-verbal ability relationships. The study of cognitive processes in interaction and embedded in meaningful tasks is discussed.     

Time in a timeless environment

The fact that every organism possesses an endogenous biological clock can be established when they are made to live in conditions of timelessness. How do human beings perform under such conditions? Human isolation facilities provide such timeless environments where human beings can live comfortably while performing various bodily activities as dictated by their endogenous clock. In this article, I narrate my personal experience in the isolation facility at Madurai Kamaraj University. My stay (on three occasions) has led to the important finding that the menstrual cycle in a human female is not coupled to the sleep-wake cycle. I also describe how such experiments can be useful in the context of shift-working, jet-lag and space studies.     

一类具有时滞病毒模型的Hopf分支

利用时滞微分方程理论与Hopf分支的相关理论,对一类具有时滞的流感病毒模型进行了研究,对其惟一的正平衡点,给出了其存在Hopf分支的条件和分支方向.     

Visual and phonological determinants of misreadings in a transparent orthography

Growth of word reading skills was examined in first and second year Italian school children by analysis of the pattern of reading errors. The study was designed to investigate the role of visual vs phonological similarities as causes of misreadings in a transparent orthography. The selection of reading material was tailored to permit a meaningful cross-language comparison with pre-existing findings on English-speaking children. The results showed that, in Italian as in English, spatially-related errors (such as confusingb andd) constituted a minor proportion of the total errors. Errors on vowel and consonant letters that are not spatially confusable accounted for the greater proportion of the total. Moreover, the co-occurrence of spatial and phonological confusability resulted in appreciably more errors than when either occurred without the other. Vowel position in the syllable had no systematic effect on errors. In beginning readers of Italian, consonant errors outnumbered vowel errors by a wide margin; the reverse pattern was found in previous studies on English-speaking children at the same level of schooling. It is proposed that differences between Italian and English in the phonological structure of the lexicon and in the consistency of grapheme-phoneme correspondences account in large part for the differences in quantity and distribution of the errors.     

Predicting delay in reading achievement in a highly transparent language

A random sample of 91 preschool children was assessed prior to receiving formal reading instruction. Verbal and nonverbal measures were used as predictors for the time of instruction required to accurately decode pseudowords in the highly orthographically regular Finnish language. After 2 years, participants were divided into four groups depending on the duration of instruction they had required to reach 90 % accuracy in their reading of pseudowords. Participants were classified as precocious decoders (PD), who could read at school entry; early decoders (ED), who learned to read within the first 4 months of Grade 1; ordinary decoders (OD), who learned to read within 9 months; and late decoders (LD), who failed to reach the criterion after 18 months of reading instruction at Grade 2. Phonological awareness played a significant role only in differentiating PD from ED and OD. However, phonological awareness failed to predict the delayed learning process of LD. LD differed from all other groups in visual analogical reasoning in an analysis not containing phonological awareness measures. Letter knowledge and visual analogical reasoning explained above 90% of the PD-LD difference. Preschool composite (objects, colors, and digits) naming speed measures best predicted reading fluency at the end of Grade 2. The supportive role of orthographic knowledge in phonological awareness, the role of visual analogical reasoning, and the inability of phonological measures to discriminate late decoders are discussed.     

Learning Prolog in a schema-based environment

A set of basic construct Prolog schemata are presented as the basic constructs of a structured Prolog for recursive list processing. Prolog schema hierarchies are given that group classes of Prolog programs within each of the basic construct Prolog schemata via most-specific schemata which high-light their similarities and differences. A schema-based instructional approach based upon this classification of Prolog programs is provided as a method of introducing recursion to novice Prolog programmers. The incorporation of this approach to teaching recursive Prolog programming in an intelligent tutoring system is presented. Finally, a schema-based Prolog programming environment embedding this tutoring system in addition to a standard Prolog development system is proposed which promotes the acquisition and use of structured programming constructs in Prolog.     

Developing multiliteracies in a technology-mediated environment

Evolving technologies and globalisation presents educators with the challenge of creating learning experiences to help students develop competencies to enable them to function successfully in a dynamic society. Today’s learner is expected to be multiliterate – able to analyse and construct multi-modal texts. A qualitative embedded multi-case study was conducted to investigate the learning experiences and multiliteracy outcomes for students engaged in an educational program with a media studies focus. The program, designed for a secondary school English curriculum, was underpinned by multiliteracies pedagogy and delivered within a technology-mediated environment. This paper reports a single class case drawing upon examples from small group cases embedded within the class. The findings suggest that educational programs underpinned by multiliteracy pedagogy supported by technology can provide meaningful learning experiences for students whilst achieving multiliteracies focused learning outcomes. For this to occur important factors such as teacher technology competencies and expertise, access and integration of technology and facilitation of effective learning scaffolds should be considered.     

Pedagogic affect and its politics: learning to affect and be affected in education

ABSTRACT

This paper examines the critical contribution that affects as bodily capacities to act, engage and connect can make to children’s learning in museums and schools. Drawing chiefly on empirical material collected over the course of visits by school children to Museums Victoria, Australia, and bringing a sociomaterial sensibility to bear, I trace the movements of these children through exhibition spaces and show pedagogic affect at work. I argue that children’s learning can usefully be understood in ways that go beyond social constructivism which underwrites museum learning and school education yet tends to neglect the role of affectivity and material agency in learning, as well as relations of power. As the empirical material shows, the politics of affective practice involve the co-constitution of bodies, spaces and objects in ways that actively intervene in established relations of power. I conclude by calling for a renewed engagement with the affective in education.     

Contextual stimuli and memory retrieval in pigeons

Pigeons were given free-operant successive discrimination training in which, on alternate days, two different interdimensional problems were employed (color positive and line angle negative; a different color negative and a different line angle positive). Between days, these problems could be construed as intradimensional ones. For one group, training was conducted on each problem in the presence of the same ambient (contextual) stimuli, while for a second group each problem was trained in a different context. For a third group, these two contexts were randomly related to the problems. Postdiscrimination stimulus generalization gradients showed that peak shifts were obtained in both the same context and the random context groups, but no peak shifts were found for the group which learned each problem in a different context. Results were consistent with Spear’s (1973) treatment of animal memory which attributes retention test performance to the operation of a “context-elicited” retrieval process. An alternative uniprocess conditioning account of these and similar data was also discussed.