Sources of Differences in Children's Understandings of Mathematical Equality: Comparative Analysis of Teacher Guides and Student Texts in China and the United States

This study reports findings from comparative samples of sixth-grade Chinese and U.S. students' interpretations of the equal sign. Ninety-eight percent of the Chinese sample correctly answered 4 items indicating conceptions of equality and provided conceptually accurate explanations. In contrast, only 28% of the U.S. sample performed at this level. We examine how teacher preparation materials, students' textbooks and teachers' guidebooks treat equality in each country. U.S. teacher preparation textbooks rarely interpreted the equal sign as equivalence. On the contrary, Chinese textbooks typically introduced the equal sign in a context of relationships and interpreted the sign as “balance,” “sameness,” or “equivalence” and only then embedded the sign with operations on numbers.     

Differential Prediction of Preparatory and Performance Self-Efficacy Judgments

This study examined the effects of self-efficacy in preparatory and performance contexts. We conducted a longitudinal study of 63 students' exam preparation and performance. Three waves of data were collected in conjunction with course exams. Within each wave, self-efficacy was assessed at 2 time points, 1 week before the exam (preparatory self-efficacy) and within the 24 hr preceding the exam (performance self-efficacy). We expected preparatory and performance self-efficacy to predict exam preparation and performance, respectively. Multilevel analysis revealed that the effects of preparatory self-efficacy depended on the level of analysis, but performance self-efficacy had positive effects on exam performance at the between- and within-person levels of analysis. Our results suggest that timing of self-efficacy assessment matters as the effects of self-efficacy depend on the context.     

A Preliminary Study of DSM–5 PTSD Symptom Patterns in Veterans by Trauma Type

The all-volunteer status of the military, combined with an increasing desire to employ individuals with the requisite knowledge, skills, and abilities to perform highly sophisticated tasks, has intensified competition between military and private sector organizations attempting to attract and retain qualified personnel. In an effort to remain competitive with employers in the private sector labor market, U.S. military organizations have directed their attention to various personnel support programs aimed at meeting the needs of servicemembers and contributing to their overall quality of life. More specifically, these military services have focused on the development and validation of conceptual models that link quality of life to desired military outcomes, including personnel retention, readiness, and performance. This study extended recent quality of life research efforts by determining the applicability of a model developed and validated for Navy personnel to another branch of the military, the U.S. Marine Corps. Structural equation modeling results suggested that the Navy model provided an adequate fit to the Marine Corps data for each of the subgroups considered. Results and implications are discussed.     

Basic number processing in children with specific learning disorders: Comorbidity of reading and mathematics disorders

As well as being the hallmark of mathematics disorders, deficits in number processing have also been reported for individuals with reading disorders. The aim of the present study was to investigate separately the components of numerical processing affected in reading and mathematical disorders within the framework of the Triple Code Model. Children with reading disorders (RD), mathematics disorders (MD), comorbid deficits (RD + MD), and typically developing children (TD) were tested on verbal, visual-verbal, and nonverbal number tasks. As expected, children with MD were impaired across a broad range of numerical tasks. In contrast, children with RD were impaired in (visual-)verbal number tasks but showed age-appropriate performance in nonverbal number skills, suggesting their impairments were domain specific and related to their reading difficulties. The comorbid group showed an additive profile of the impairments of the two single-deficit groups. Performance in speeded verbal number tasks was related to rapid automatized naming, a measure of visual-verbal access in the RD but not in the MD group. The results indicate that deficits in number skills are due to different underlying cognitive deficits in children with RD compared to children with MD: a phonological deficit in RD and a deficit in processing numerosities in MD.     

Inattention,working memory,and academic achievement in adolescents referred for attention deficit/hyperactivity disorder (ADHD)

This study investigated the role of inattention and working memory in predicting academic achievement in 145 adolescents aged 13 to 18 referred for attention deficit/hyperactivity disorder (ADHD). Path analysis was used to examine whether auditory-verbal and visual-spatial working memory would mediate the relationships between classroom inattention symptoms and achievement outcomes. Results provide support for the mediational model. Behavioral inattention significantly predicted both auditory-verbal and visual-spatial working memory performance. Auditory-verbal working memory was strongly associated with adolescents' achievement in reading and mathematics, while visual-spatial working memory was only associated with achievement in mathematics. The path from inattention symptoms to reading was partially mediated by the working memory variables, but the path from inattention to mathematics was not mediated by working memory. The proposed model demonstrated a good fit to the data and explained a substantial amount of variance in the adolescents' achievement outcomes. These findings imply that working memory is a risk factor for academic failure for adolescents with attentional problems.     

Total spin in the density matrix renormalization group algorithm

A new density matrix renormalization group (DMRG) algorithm is presented which conserves the total spin. This is the first time that standard DMRG is extended to exploit fully the symmetries of the Hamiltonian. The obtained general procedure works for any operator, even operators that do not commute with the Hamiltonian. The new method gives substantial improvements over the standard DMRG.     

Historical Contingency and the Impact of Scientific Imperialism

In a recent article in this journal, Steve Clarke and Adrian Walsh propose a normative basis for John Dupré's criticisms of scientific imperialism, namely that scientific imperialism can cause a discipline to fail to progress in ways that it otherwise would have. This proposal is based on two presuppositions: one, that scientific disciplines have developmental teleologies, and two, that these teleologies are optimal. I argue that we should reject both of these presuppositions and so conclude that Clarke and Walsh's proposal is insufficiently warranted for it to provide a normative basis for criticisms of scientific imperialism.     

A view from the visitors' gallery

SUMMARY

In this paper, the author describes aspects of his work as a psychoanalytical psychotherapist in a hospital for diseases of the colon and rectum. After reviewing some of the earlier psychoanalytic literature (Freud and Abraham), and more recent theoretical contributions, two cases are described in some detail, which help give a flavour to some of the work. The paper concludes with caveats about the internal and external working environment, which will facilitate or hinder working in particular medical settings.     

Idiographic autobiographical memories in major depressive disorder

When cued with generic happy and sad words, depressed individuals have been found to articulate contextually impoverished, overgeneral memories of both positive and negative autobiographical events. The current study tested whether overgeneral memory is observed outside of the cue-word paradigm. Currently depressed, formerly depressed, and never-depressed controls underwent an idiographic interview procedure in which participants generated memories of their happiest and saddest lifetime events. Although depressed and nondepressed participants did not differ with respect to the specificity, retrieval difficulty, and emotionality of their saddest memories, depressed individuals' happiest memories were less specific, harder to retrieve, and less emotional than were nondepressed participants' happiest memories. The memory characteristics of formerly depressed participants largely resembled those of healthy controls. Overall, the present results suggest that meaningful cues trigger mood-congruent memory processing in currently, but not in formerly, depressed individuals.