Using profile expansion techniques to alleviate the new user problem

Collaborative Filtering techniques have become very popular in the last years as an effective method to provide personalized recommendations. They generally obtain much better accuracy than other techniques such as content-based filtering, because they are based on the opinions of users with tastes or interests similar to the user they are recommending to. However, this is precisely the reason of one of its main limitations: the cold-start problem. That is, how to recommend new items, not yet rated, or how to offer good recommendations to users they have not information about. For example, because they have recently joined the system. In fact, the new user problem is particularly serious, because an unsatisfied user may stop using the system before it could even collect enough information to generate good recommendations. In this article we tackle this problem with a novel approach called “profile expansion”, based on the query expansion techniques used in Information Retrieval. In particular, we propose and evaluate three kinds of techniques: item-global, item-local and user-local. The experiments we have performed show that both item-global and user-local offer outstanding improvements in precision, up to 100%. Moreover, the improvements are statistically significant and consistent among different movie recommendation datasets and several training conditions.     

Revisions to rationality: the translation of ‘new knowledges’ into policy under the Coalition Government

This article gives an account of the use of knowledges from emerging scientific fields in education and youth policy making under the Coalition government (2010–15) in the UK. We identify a common process of ‘translation’ and offer three illustrations of policy-making in the UK that utilise diverse knowledges produced in academic fields (neuroscience, network theory and well-being). This production of ‘new knowledges’ in policy contexts allows for the identification of sites of policy intervention. This process of translation underlies a series of diverse revisions of the rational subject of policy. Collectively, these revisions amount to a change in policy-making and the emergence of a different subject of neoliberal policy. This subject is not an excluded alterity to an included rational subject of neoliberalism, but a ‘plastic subject’ characterised by its multiplicity. The plastic subject does not contradict the rational subject as central to neoliberal policy-making, but diversifies it.     

Cultural discontinuity between home and school and American Indian and Alaska Native children's achievement

An assumption of culture-based education with respect to American Indian and Alaska Native (AI/AN) children is that discontinuity between home and school cultures is responsible for educational underachievement. Using data from the 2009 round of the National Indian Education Study, a subset of the larger National Assessment of Education Progress (NAEP), the author constructed a measure of cultural discontinuity and examined its relationship to AI/AN students' Grade 4 and 8 reading and mathematics achievement. Contrary to the cultural discontinuity hypothesis, there is no statistically significant negative relationship when the culture of the home is discontinued at school. On the Grade 4 NAEP reading assessment, in particular, cultural discontinuity was positively associated with students' achievement, net of both student- and school-level controls. Findings suggest that the assumptions of culture-based education may be overstated, though longitudinal data are still needed to be able to make causal claims.     

Effects of 10-week eccentric overload training on kinetic parameters during change of direction in football players

ABSTRACT

The aim of the current study was to analyse the effect of 10-week eccentric overload training on kinetic parameters during change of direction (COD) in U-19 football players. The outcome measured included relative peak braking (rPB) and propulsive force (rPF), contact time (CT), time spent during braking (BT) and propulsive phase (PT), relative total (rTOT_IMP), braking (rB_IMP) and propulsive (rP_IMP) impulses. Between-group results showed a substantial better improvement (likely) in CT (ES: 0.72) and BT (ES: 0.74) during side-step cutting, and in rPB (ES: 0.84) and rB_IMP (ES: 0.72) during crossover cutting, in the experimental group (EXP) in comparison to control group (CON). Within-group analysis showed a substantially better performance (likely to almost certain) in CT (ES: 1.19), BT (ES: 1.24), PT (ES: 0.70), rPB (ES: 0.75), rPF (ES: 0.68), rTOT_IMP (ES: 0.48) and rB_IMP (ES: 0.50) in EXP during side-step cutting. Regarding crossover cutting, within-group analysis showed a substantial better performance (likely to almost certain) in CT (ES: 0.75), rPB (ES: 0.75), rPF (ES: 1.34), rTOT_IMP (ES: 0.61), rB_IMP (ES: 0.76) and rP_IMP (ES: 0.46) in EXP. In conclusion, the eccentric overload-based programme led to an improvement in kinetic parameters during COD football tasks.     

Transitions in the manifestations of the research culture of Spanish universities

Universities must adapt to the challenges of social competitiveness and its new demands but there is still little evidence of how these changes are perceived by the academics. This paper provides insight on this matter and analyses the research culture of five Spanish universities from the perspective of the different academic bodies. A qualitative methodology was employed in the study based on 43 in-depth interviews with institutional leaders (vice-rectors and managers), responsible for research activity, (directors of research centres) and individual researchers (doctoral and postdoctoral researchers). The results point to a clear change in the institutional mission that moves from an institutional model where teaching and research cohabitate together towards another where research activity intensifies. The manifestations of the new research culture is characterised by the quest for efficiency and competitiveness at all levels and bodies. Despite the changes in the university model, participants perceive that the traditional and new models coexist and affect the university structure, the functioning of the centres and departments and the dynamics of the research teams which causes dissatisfaction of the researchers that in this context have to deal with the increasing pressure to publish and obtain external funding to assure ‘survival’. The research culture is also characterised as one that moves towards the scarcity of support measures for training, the confusion perceived between the political discourse and academic practice and the attempt to reposition the university in a social context, through redefining its role and fostering transfer activities.     

Failed regulations and school composition: selective admission practices in Chilean primary schools

This is an exploratory study about pupil selection. Admission regulations are central to understanding issues of school mix, segregation and educational justice. In Chile, student selection has been intensively discussed but scarcely studied. Using a questionnaire for headteachers (N = 581), we explore how school admission processes are organised and implemented within a market-based educational system with a high-stakes testing regime where schools are pushed to use selection practices. Despite the existence of a national (although weak) legal prohibition at the time the survey was conducted, half of the headteachers state that they use some mechanism to select students (play sessions, student testing, or interviews with parents) even when they do not face demand pressures. Exploratory data suggest higher levels of selectivity in subsidised private schools. Regression analysis shows a strong association between ‘selectivity’ and homogeneous academic intake and social composition. Presumably, the widespread use of selection procedures responds to the structuring force of a double system of educational accountability; strong pressure on performance within a testing regime and where funding depends on enrolments makes selection a fundamental strategy for schools, but which is seriously affecting equality goals.     

Exploring the Effectiveness of a Measurement Error Tutorial in Helping Teachers Understand Score Report Results

The goal of this study was to explore the effectiveness of a short web-based tutorial in helping teachers to better understand the portrayal of measurement error in test score reports. The short video tutorial included both verbal and graphical representations of measurement error. Results showed a significant difference in comprehension scores between each of two tutorial groups (basic and enhanced) and the control group (no tutorial) but not between the two tutorial groups. Results also provided evidence of teachers' misconceptions about the meaning of measurement error and confidence bands.     

Five-year longitudinal evaluation of quality of life in a cohort of patients with differentiated thyroid carcinoma

Differentiated thyroid carcinoma (DTC) generally has a favorable outcome. Thyroid disease, treatments, stress, and comorbidity can compromise health-related quality of life (QoL) and indirectly weigh upon the outcome. From 2004 to 2008, we evaluated QoL longitudinally in 128 DTC subjects. During scheduled examinations, subjects were asked to undergo a semi-structured psychiatric interview and five rated inventories. The same examination was conducted in 219 subjects after surgery for benign thyroid pathology. Low scores represent a better QoL. DTC and control subjects were similar in terms of age, male/female ratio, concomitant psychopharmacological treatments, and frequency of psychiatric diseases. In DTC subjects, Billewicz scale (BS) scores showed an increasing trend over time, especially among females. The ad hoc thyroid questionnaire (TQ) scores were similar in both groups and did not change over time, but at the end of the study ad hoc TQ and BS were significantly related. Ad hoc TQ scores were also related to age on entry to the study. In both male and female DTC subjects, Hamilton’s tests for anxiety (HAM-A), but not for depression (HAM-D), showed an improving trend. At the end of the study, HAM-A and HAM-D scores were comparable to those of the control group. HAM-A and HAM-D were both positively correlated with the stage of cancer and the time between diagnosis and treatment. Only HAM-D correlated with age on entry to the study. Kellner symptom questionnaire (KSQ) item scores were higher in DTC subjects than in controls. The change over time in the items including anxiety, somatization, depression, and hostility was significant. Somatization and hostility were more significantly reduced in DTC females than in DTC males. Hostility scores were significantly lower in DTC subjects than in controls at the end of the study. Somatization and depression were significantly related to staging on diagnosis and age on entry to the study. Our study confirms a wide variation of illness perception in DTC subjects, which is generally unrelated to the favorable clinical follow-up of the disease. Psychological evaluation during long-term follow-up improved QoL scores, which reached the same levels noted in subjects with a history of thyroid surgery for benign thyroid pathology. Our data indicate that special attention should be paid to QoL in older DTC subjects and those with more severe staging on diagnosis.     

Self-Regulation Abilities and Spanish-Speaking Preschoolers’ Vocabulary and Letter-Word Skills in Spanish and English

Research Findings: This study examined the heterogeneity in Spanish-speaking children's (N = 117; M age = 53 months; SD = 5 months; 57% boys) vocabulary and letter-word skills in English and Spanish after one year of preschool and the extent to which early self-regulation abilities (i.e., executive function and effortful control) were associated with that variability. Data were gathered via teacher and parent surveys and standardized assessments. Three distinct profiles of Spanish-speaking preschoolers were identified using cluster analysis. One group exhibited high levels of Spanish and English vocabulary and letter-word skills (a.k.a. high-balanced bilinguals). The other two groups exhibited predominantly Spanish or English vocabulary and letter-word skills (a.k.a. Spanish- or English-dominant). Multinomial logistic regression analyses (controlling for children's nonverbal cognitive ability) revealed that effortful control skills enhanced children's probability of being classified as high-balanced bilinguals versus Spanish-dominant; however, this was evident only for the children whose parents reported speaking exclusively Spanish at home. Executive function abilities appeared to be unrelated to preschoolers' bilingual classification, and thus their English vocabulary and letter-word skills. Practice or Policy: The findings have implications for early education programs working to increase the school readiness of Spanish-speaking children by highlighting the key role that effortful control may play in supporting their learning of English skills, particularly for those whose parents speak exclusively Spanish at home.