Woodward’s synthesis of vitamin B<Subscript>12</Subscript>

The synthesis of this molecule was a landmark in organic synthesis. It involved the masterful control of shapes of molecules to create 9 chiral centres with known absolute and relative configurations. The concepts of absolute and induced asymmetric synthesis are here explained.     

The role of sensory preconditioning in memory retrieval by preverbal infants

Infants’ memories are highly specific to their training stimuli; they rarely transfer learned responding. In two experiments, we asked whether sensory preconditioning facilitates the transfer of deferred imitation. In Experiments 1A and 1B, 6-month-olds were simultaneously preexposed to Puppets A and B and then saw target actions modeled on Puppet A. The infants associated the paired puppets and imitated the actions on Puppet B. In Experiment 2, the preexposure procedure was repeated, but the actions were modeled on Puppet A with a toy train in view. The infants also associated Puppet A and the train: Either object effectively reactivated both forgotten memories; thereafter, the infants again imitated the actions on Puppet B. These findings reveal that infants form specific and enduring associations between stimuli they have merely seen together. These associations facilitate the transfer of deferred imitation, both directly and indirectly, through connections to other associations.     

Evaluation of an Innovative Mathematics Program in Terms of Classroom Environment,Student Attitudes,and Conceptual Development

Dull classroom environments, poor students’ attitudes and inhibited conceptual development led to the creation of an innovative mathematics program, the Class Banking System (CBS), which enables teachers to use constructivist ideas and approaches. To assess the effectiveness of the CBS, the Individualised Classroom Environment Questionnaire (ICEQ), Constructivist Learning Environment Survey (CLES), Test of Mathematics-Related Attitudes (TOMRA), and concept map tests were administered to two groups of fifth-grade students as pretests and posttests over an academic year. To enrich the data collected from those questionnaires, three case studies (one for the experimental group and two for the control group) were undertaken based on observations and interviews of selected students. Relative to non-CBS students, CBS students experienced more favorable changes in terms of mathematics concept development, attitudes to mathematics, and perceived classroom environments on several dimensions of the CLES (e.g., Personal Relevance, Shared Control) and the ICEQ (e.g., Participation and Differentiation). Qualitative information based on classroom observations and student interviews reinforced and enriched the patterns of results obtained from the concept test and questionnaires.     

Effects of within-class ability grouping on social interaction,achievement, and motivation

This study examined how grouping arrangements affect students achievement, social interaction, and motivation. Students of high, average and low ability were randomly assigned to homogeneous or heterogeneous ability groups. All groups attended the same plant biology course. The main results indicate that low-ability students achieve more and are more motivated to learn in heterogeneous groups. Average-ability students perform better in homogeneous groups whereas high-ability students show equally strong learning outcomes in homogeneous and heterogeneous groups. Results on social interaction indicate that heterogeneous groups produce higher proportions of individual elaborations, whereas homogeneous groups use relatively more collaborative elaborations. In the discussion, these differences in social interaction are used to explain the differential effects of grouping arrangements on achievement scores. Practical implications are discussed and topics for further research are advanced.     

Investigating profiles of lexical quality in preschool and their contribution to first grade reading

This longitudinal study investigated profiles of lexical quality domains in preschool children and the extent to which profile membership predicted reading comprehension in first grade. A latent profile analysis was conducted to classify 420 preschool children on lexical quality domains, including orthography, phonology, morphosyntax, and vocabulary. Regression analysis was used to determine whether profile membership was associated with first grade outcomes across reading comprehension and its components (i.e., listening comprehension and word recognition). Results revealed five profiles of lexical quality which were predictive of all three outcomes in first grade. Children in low lexical quality profiles performed more poorly on the outcome measures than children in the higher lexical quality profiles. Additionally, profile membership did differentially predict later reading outcomes. These results suggest that lexical quality profiles are associated with reading and therefore may offer a means of early identification of children who are susceptible to future reading difficulties.     

Visual Chunking Skills of Hong Kong Children

This study investigated the development of visual chunking skills in the processing of Chinese characters among Hong Kong pupils. One-hundred-seventy-nine primary school students from first, second and fourth grades were administered a character copying task. Children as young as 6 years of age were aware of character units and were able to apply visual chunking strategies when processing characters. Children in higher grades performed better than those in lower grades on every character type, and the types of errors they made revealed that their chunking level was higher than that of younger children. Differences between ability groups emerged in second grade and vanished in fourth grade, suggesting that children with a lower reading ability are slower to develop advanced chunking skills.     

教育制度:概念的厘定

虽然要对教育制度下一个准确的、为各方所认可的定义十分困难 ,但我们认为 ,一个完整准确的教育制度定义 ,至少应当包含以下几个基本的方面 :即 ,教育制度是教育活动的规则 ;教育制度是“社会的”制度 ;教育制度具有程度不同的权威性或强制性。在此基础上 ,我们可以将“教育制度”概念大致地界定为 :教育制度是用以调整个体行动者之间以及特定教育组织内部行动者之间关系的强制性或权威性的行为规则体系     

Using Photography To Explore Hidden Realities and Raise Cross-Cultural Sensitivity in Future Teachers

This study explored the influence of residency status (outsider) and prior cross-cultural experiences on how the neighborhoods of students are perceived by future teachers. The study participants consisted of 18 graduate teacher education mentors and their 18 high school mentees. The data sources included 820 black and white photographs and 82 photo captions generated by the study participants, mentee/mentor group discussions, and the graduate students’ weekly reflective journals, bi-weekly facilitated discussions and peer debriefings. The study found that subconscious realities based on prior cross-cultural experiences (or the lack thereof) are more significant factors than residency status when making value judgment about the neighborhoods of “others.” Elinor L. Brown is an Assistant Professor in the Department of Curriculum and Instruction, University of Kentucky, 311 Dickey Hall, Lexington, KY 40506-0017