492 research outputs found

    To let students self-select or not: that is the question for teachers of culturally diverse groups

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    When students can self-select their group members, a common assumption is that students prefer to select friends from similar cultural backgrounds. However, when teachers randomise students in groups from different cultural backgrounds, students are “forced” to work together. The prime goal of this study is to understand the impact of two group selection methods on how students from diverse cultural backgrounds build learning and work-relations, using an innovative quantitative method of Social Network Analysis in a pre-post test manner. In a quasi-experimental study of 2 ˣ 69 students, in one condition the students were randomly allocated to groups by staff and in the other students were allowed to self-select their group members. The results indicate that students in the self-selected condition primarily selected their friends from a similar cultural background. The learning networks after 14 weeks were primarily predicted by the group allocation and initial friendships. However, students in the random condition developed equally strong internal group relations but more “knowledge spillovers” outside their group, indicating that the random condition led to positive effects beyond the group

    Ensuring Uniformity in Random Peer Sampling Services

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    The peer sampling service is a core building block for gossip protocols in peer-to-peer networks. Ideally, a peer sampling service continuously provides each peer with a sample of peers picked uniformly at random in the network. While empirical studies have shown that uniformity was achieved, analysis proposed so far assume strong restrictions on the topology of the overlay network it continuously generates. In this work, we analyze a Generic Random Peer Sampling Service (GRPS) that satisfies the desirable properties for any peer sampling service –small views, uniform sample, load balancing, and independence– and relieve strong degree connections in the nodes assumed in previous works. The main result we prove is: starting from any simple (without loops and parallel edges) directed graph with out-degree equal to c for all nodes, and recursively applying GRPS, eventually results in a random simple directed graph with out-degree equal to c for all nodes. We test empirically convergence time and independence time for GRPS. We use this empirical evaluation to show that GRPS performs better than previously presented peer sampling services. We also present a variant of GRPS that ensures that the in and out-degrees of nodes in the initial network are maintained in the resulting graph. Finally, we discuss on how to deal with new nodes in both settings

    PRISM (Program of Resources, Information and Support for Mothers) Protocol for a community-randomised trial [ISRCTN03464021]

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    BACKGROUND: In the year after birth one in six women has a depressive illness, and 30% are still depressed, or depressed again, when their child is 2 years old, 94% experience at least one major health problem (e.g. back pain, perineal pain, mastitis, urinary or faecal incontinence), 26% experience sexual problems and almost 20% have relationship problems with partners. Women with depression report less practical and emotional support from partners, less social support overall, more negative life events, and poorer physical health. Their perceptions of factors contributing to depression are lack of support, isolation, exhaustion and physical health problems. Fewer than one in three affected women seek help in primary care despite frequent contacts. METHODS/DESIGN: PRISM aims to reduce depression and physical health problems of recent mothers through primary care strategies to increase practitioners' response to these issues, and through community-based strategies to develop broader family and community supports for recent mothers. Eligible local governments will be recruited and randomised to intervention or comparison arms, after stratification (urban/rural, size, birth numbers, extent of community activity), avoiding contiguous boundaries. Maternal depression and physical health will be measured six months after birth, in a one year cohort of mothers, in intervention and comparison communities. The sample size to detect a 20% relative reduction in depression, adjusting for cluster sampling, and estimating a population response fraction of 67% is 5740 × 2. Analysis of the physical and mental health outcomes, by intention to treat, will adjust for the correlated structure of the data

    Set up and assessment of progression criteria for internal pilots:the Brushing RemInder 4 Good oral HealTh (BRIGHT) trial example

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    Background Dental caries is common in young people and has wide-ranging ramifications for health and quality of life. Text messaging interventions show promise as a means to promote oral health behaviour change among young people. This paper reports the internal pilot of the Brushing RemInder 4 Good oral HealTh (BRIGHT) trial, which is evaluating an intervention comprising an oral health classroom lesson and text messages about toothbrushing, on caries in young people. Pilot trial objectives were to evaluate the feasibility and appropriateness of recruitment and data collection methods, the randomisation strategy, and intervention delivery against progression criteria for the main trial. Methods This is an internal pilot trial embedded within an assessor-blinded, two-arm, cluster randomised controlled trial. Participants were pupils aged 11–13 years (in year 7/S1 or year 8/S2) in secondary schools in England, Scotland, and Wales with above average pupil eligibility for free school meals. Following completion of pupil baseline questionnaires and dental assessments, year groups within schools were randomised to the intervention or control arm. Approximately 12 weeks later, participants completed a follow-up questionnaire, which included questions about sources of oral health advice to assess intervention contamination between year groups. At the end of the pilot phase, trial conduct was reviewed against pre-specified progression criteria. Results Ten schools were recruited for the pilot, with 20 year groups and 1073 pupils randomised (average of 54 pupils per year group). Data collection methods and intervention delivery were considered feasible, the response rate to the follow-up questionnaire was over 80%, there was an indication of a positive effect on self-reported toothbrushing, and interest was obtained from 80% of the schools required for the main trial. Despite partial intervention contamination between year groups, within-school randomisation at the level of the year-group was considered appropriate for the main trial, and the sample size was revised to account for partial contamination. Facilitators and barriers to recruitment and data collection were identified and strategies refined for the main trial. Conclusions Progression to the main trial of BRIGHT, with some design refinements, was concluded. The internal pilot was an efficient way to determine trial feasibility and optimise trial processes
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