An experimental comparison of a genetic algorithm and a hill-climber for term selection

Purpose – The term selection problem for selecting query terms in information filtering and routing has been investigated using hill-climbers of various kinds, largely through the Okapi experiments in the TREC series of conferences. Although these are simple deterministic approaches which examine the effect of changing the weight of one term at a time, they have been shown to improve the retrieval effectiveness of filtering queries in these TREC experiments. Hill-climbers are, however, likely to get trapped in local optima, and the use of more sophisticated local search techniques for this problem that attempt to break out of these optima are worth investigating. To this end, we apply a genetic algorithm (GA) to the same problem. Design/Methodology/Approach – We use a standard TREC test collection from the TREC-8 filtering track, recording mean average precision and recall measures to allow comparison between the hillclimber and GA algorithms. We also vary elements of the GA, such as probability of a word being included, probability of mutation and population size in order to measure the effect of these variables. Different strategies such as Elitist and Non-Elitist methods are used, as well as Roulette Wheel and Rank selection GA algorithms. Findings – The results of tests suggest that both techniques are, on average, better than the baseline, but the implemented GA does not match the overall performance of a hill-climber. The Rank selection algorithm does better on average than the Roulette Wheel algorithm. There is no evidence in this study that varying word inclusion probability, mutation probability or Elitist method make much difference to the overall results. Small population sizes do not appear to be as effective as larger population sizes. Research limitations/implications – The evidence provided here would suggest that being stuck in a local optima for the term selection optimization problem does not appear to be detrimental to the overall success of the hill-climber. The evidence from term rank order would appear to provide extra useful evidence which hill-climbers can use efficiently and effectively to narrow the search space. Originality/Value – The paper represents the first attempt to compare hill-climbers with GAs on a problem of this type

Change4Life Sports Clubs research 2016 - part one report

Change4Life Sports Clubs are funded by the Department of Health and managed by the Youth Sport Trust (YST). The clubs were introduced into primary schools in 2011/12 and aim to increase the physical activity, health and wellbeing of less active 7-9 year olds through the provision of fun multi-sport themes and healthy lifestyle activities. The success of the clubs has resulted in additional funding to expand the programme as a central part of a broader healthy lifestyle offer in schools. This is supported by the development of a hub of expertise focused in the areas of greatest health inequalities (priority areas) to support and share effective practice among schools and local authority Health and Wellbeing boards. In 2015, spear produced a Lifetime Impact Evaluation of the Change4Life Sports Clubs (2011-2015). The evaluation incorporated a controlled experimental evaluation at the forefront of research in the social sciences and NESTA rated 4-5. Data from over 7,500 children in more than 500 clubs showed that Change4Life Sports Clubs have a significant, positive impact on the activity levels, health behaviours and wellbeing of participating children. The Lifetime Evaluation Report included a number of recommendations for enhancing and building upon the evidence base for the programme. These recommendations included assessing the effectiveness of programme infrastructure in the sustainability of the clubs, assessing programme alignment with public health priorities and exploring the possibility of an economic assessment of the impact of the programme. The Change4Life Sports Clubs Research 2016 has three key objectives: 1. Demonstrate the wider impact of the Change4Life Sports Clubs 2. Assess the value for money and return on investment of the Change4Life Sports Clubs 3. Capture good practice for embedding and sustaining the programme (locally and nationally) This Part 1 Report examines the evidence of the wider impact of Change4Life Sports Clubs (objective 1), explored and presented in 5 main sections: 1.Evaluation of the wider impact of Change4Life Sports Clubs on healthy lifestyles 2.Evaluation of the wider impact of Change4Life Sports Clubs on behaviour and engagement 3.Exploration of how the Change4Life Sports Clubs are being embedded and sustained in schools 4.Exploration of how the Change4Life Sports Clubs programme supports whole school agenda 5.Exploration of how the Change4Life Sports Clubs programme supports public health priorities The final section of this report presents 6 area profiles to provide a geographical context to the wider impact of the Change4Life Sports Clubs

Value for money & return on Investment of Change4Life Sports Clubs – part 2

Headlines Unit Outcome and Unit Cost Analyses • Change4Life Sports Clubs have a cost of £305 for every new child meeting CMO physical activity guidelines, for which cost an additional 0.2 children were lifted out of inactivity and a further 2.2 children were lifted out of low activity, with each of these children experiencing an average increase in reported wellbeing and individual development outcomes of 71%. • In comparison to the control condition counterfactual, Change4Life Sports Clubs delivered the following NET outcomes per £1,000 of expenditure: • 41 participants • 0.8 sustained clubs • 3.9 Young Leaders • 2.8 new children meeting CMO physical activity guidelines • 8.4 children lifted out of low activity • 1.3 children lifted out of inactivity • 0.1 children newly eating 5-a-day • 0.6 children reporting increased wellbeing and individual development outcomes • 5.1 children starting with low activity levels reporting increased wellbeing and individual development outcomes. Quality Adjusted Life Year (QALY) Analysis • The cost per QALY generated for the GROSS outcomes of Change4Life Sports Clubs is £3,385 (range:£3,036 to £3,806). • In comparison to the control condition counterfactual, the cost per QALY generated for the NET outcomes of Change4Life Sports Clubs is £3,791 (range: £3,413 to £4,245). • The cost per QALY generated for Change4Life Sports Clubs is significantly below NICE’s threshold for value for money per QALY of £20,000. • The cost per QALY generated for the GROSS outcomes of Change4Life Sports Clubs compares favourably to GROSS outcomes estimated for walking buses (£4,008 per QALY), dance classes (£27,570 per QALY), free swimming (£40,462 per QALY) and community sports (£71,456 per QALY). • The cost per QALY generated by the NET outcomes of exercise referral interventions in adulthood is approximately five and a half times greater than that of Change4Life Sports Clubs. Analysis of Future Health at Ages 13-15 • The Change4Life Sports Clubs cohort are predicted to do around an hour more physical activity per week at ages 13-15 than that predicted for the control condition counterfactual, and than today’s 13-15 year olds. • The estimated additional physical activity of the Change4Life Sports Clubs cohort up to ages 13-15 will generate one additional QALY for every five children that took part in Change4Life Sports Clubs. • In comparison to the control counterfactual, the cost per QALY generated by the estimated future NET outcomes of Change4Life Sports Clubs up to ages 13-15 is £120. • Across the Health Survey for England, the Millennium Cohort Study and the Understanding Society Survey, no data is available to support a robust estimation of likely health and wellbeing status associated with physical activity levels at ages 13

Lifetime evaluation of the Change4Life Primary School Sports Club Programme

ABOUT THE PROGRAMME The Change4Life Primary School Sports Club programme is funded by the Department of Health and managed by the Youth Sport Trust. The clubs were introduced into primary schools in 2011/12 and aim to increase the physical activity, health and wellbeing of less active 7-9 year olds through the provision of fun multi-sport themes and healthy lifestyle activities. SPEAR’s evaluations of the primary programme have consistently demonstrated that Change4Life Clubs can be effective mechanisms for increasing physical activity levels among less active primary children. Through provision of a safe space to learn and play, the opportunity to contribute to club delivery and encouragement of small steps toward increasing activity levels, the clubs have helped less active children build the competencies, confidence and resilience they need to be healthy and active throughout the lifecourse. The success of the Change4Life Primary School Sports Clubs has resulted in additional funding to expand the programme as a central part of a broader healthy lifestyle offer in schools. This is supported by the development of a hub of expertise focused in the areas of greatest health inequalities (priority areas) to support and share effective practice among schools and local authority Health and Wellbeing boards. ABOUT THE EVALUATION SPEAR was commissioned from October 2013 to March 2015 to conduct a third, successive evaluation of the Change4Life Primary School Sports Club programme. In October 2014, SPEAR produced an Interim Report including impact and delivery insights and progress and planning for the primary evaluation. SPEAR also recommended inclusion of a lifetime impact assessment to provide additional value to the Final Report findings and the project end date was subsequently extended to May 2015. This Final Report both supplements and supersedes the Interim Report. SPEAR’s current evaluation of the Change4Life Clubs reflects both the changing context and priorities of the primary programme and, through a systematic, controlled experimental evaluation, provides the robust evidence base necessary to support and further the programme as it develops into the future. The 2015 Final Report presents a lifetime evaluation of the programme to date. Drawing together extant data from SPEAR’s 2011/12 and 2012/13 (2011-20133 ) evaluations with new data collated across 2013/14 and early 2014/154 (2013-20155 ), this report focuses on the lifetime impact of the clubs in key areas, namely physical activity, health behaviours and wellbeing. The report shows how delivery has evolved to address programme aims, discusses challenges faced embedding clubs as a sustainable part of schools’ healthy lifestyle offer and considers preliminary evidence of the impact of the new support framework in priority areas. Data informing this report is drawn from the survey returns of over 7,500 children participating in more than 500 Change4Life Clubs and from just under 500 children in 15 control schools. Survey completions from over 2,000 club deliverers and SGOs, telephone interviews with 39 stakeholders and data from 20 site visits complements and triangulates the experimental data allowing the experiences and perspectives of a broad range of stakeholders to be presented. Key messages are summarised at the start of each section (and in the Headlines section on pages 2-5). The report is divided into three substantive sections: Who participated? What worked? and What did the clubs look like? The Influence of the Change4Life Brand is addressed and Recommendations for the programme are presented

Embedding and sustaining Change4Life Sports Clubs: regional case studies – part three

Change4Life Sports Clubs are funded by the Department of Health (DoH) and managed by the Youth Sport Trust (YST). The clubs were introduced into primary schools in 2011/12 and aim to increase the physical activity, health and wellbeing of less active 7-9 year olds through provision of fun multi-sport themes and healthy lifestyle activities. The success of the clubs has resulted in additional funding to expand the programme as a central part of a broader healthy lifestyle offer in schools. This is supported by the development of a hub of expertise focused in the areas of greatest health inequalities to support and share effective practice among schools and local authority Health and Wellbeing boards. In 2015, spear produced a Lifetime Impact Evaluation of the Change4Life Sports Clubs, drawing on data from over 7,500 children in more than 500 clubs. The Change4Life Sports Clubs 2016 research builds upon the Lifetime Evaluation with new data from children, schools and public health directorates to address three key objectives: 1) Demonstrate the wider impact of Change4Life Sports Clubs; 2) Assess the value for money and return on investment of Change4Life Sports Clubs and; 3) Capture good practice for embedding and sustaining the programme. Part Three presents Area Case Studies for six geographical regions in England to provide insight into how the Change4Life Sports Clubs have been embedded and sustained in schools across each area: East, East Midlands, London, North East, North West and South East. Each case study is informed by (re)analysis of club deliverer and School Games Organiser (SGO) survey data, site visit case studies, and interviews conducted with Public Health Teams, senior school staff, Change4Life Sports Club Leads and SGOs. The final section of Part Three presents recommendations for embedding and sustaining the Change4Life Sports Clubs

Scattering hypervolume for ultracold bosons from weak to strong interactions

The elastic scattering properties of three bosons at low energy enter the many-body description of ultracold Bose gases via the three-body scattering hypervolume $D$. We study this quantity for identical bosons that interact via a pairwise finite-range potential. Our calculations cover the regime from strongly repulsive potentials towards attractive potentials supporting multiple two-body bound states and are consistent with the few existing predictions for $D$. We present the first numerical confirmation of the universal predictions for $D$ in the strongly interacting regime, where Efimov physics dominates, for a local nonzero-range potential. Our findings highlight how $D$ is influenced by three-body quasibound states with strong $d$-wave or $g$-wave characteristics in the weakly interacting regime.Comment: 13 pages, 8 figure

2014/15 Skills2Play/Sport programme evaluation

The Primary School Physical Literacy Framework reflects the importance of the development of children’s physical literacy; “the motivation, confidence, knowledge and understanding that provides children with the movement foundation for lifelong participation in physical activity.” It also provides clear guidance as to how schools can maximise opportunities to develop the physical literacy of their pupils. Skills2Play and Skills2PlaySport are two complementary primary school physical literacy initiatives designed to support the objectives of the new Framework. Together they comprise the Skills2Play/Sport programme. Throughout this report the term Skills2Play/Sport refers to the programme, comprising both initiatives (Skills2Play and Skills2PlaySport). The programme consists of training and a resource and equipment package, which includes activity cards for both Skills2Play (blue cards) and Skills2PlaySport (purple cards) supplied to primary school deliverers by the Youth Sport Trust. Skills2Play is targeted at Key Stage 1 (KS1) and focuses on generic skill development through a range of play activities that focus on stability, object control and locomotion. Skills2PlaySport is targeted at lower Key Stage 2 (KS2) and includes multiskill activities that build from the generic skills but also introduce the connectivity with the sports through the development of skills specific to sporting ‘themes’, namely ‘Invasion’, ‘Striking and Fielding’ and ‘Net/Wall’. Further themes are currently at varying stages of development and include ‘Aquatics’, ‘Gymnastics’, ‘Athletics’ and ‘Wheels’. ABOUT THE EVALUATION The Centre for Sport, Physical Education & Activity Research (SPEAR) was commissioned by the Youth Sport Trust to conduct an independent evaluation of the Skills2Play/Sport programme between January 2014 and July 2015. The initial stages of the evaluation focused on the pilot programme undertaken in fifty primary schools. In May 2014 SPEAR produced the Pilot Evaluation Report, which captured teachers’ experiences of the training, resources and delivery of the Skills2Play/Sport pilot programme. The programme was then rolled out to 1,000 schools nationally and the objectives of the Evaluation of the national Skills2Play/Sport programme were as follows: 1. To assess how Skills2PlaySport and Skills2Play are being delivered and sustained in primary schools to support children’s physical literacy development. 2. To investigate the impact of Skills2PlaySport on the development of lower Key Stage 2 children’s physical literacy over 12 weeks of the programme. 3. To investigate the impact of Skills2Play on the development of Key Stage 1 children’s physical literacy over 12 weeks of the programme