Compressed materialised views of semi-structured data

Query performance issues over semi-structured data have led to the emergence of materialised XML views as a means of restricting the data structure processed by a query. However preserving the conventional representation of such views remains a significant limiting factor especially in the context of mobile devices where processing power, memory usage and bandwidth are significant factors. To explore the concept of a compressed materialised view, we extend our earlier work on structural XML compression to produce a combination of structural summarisation and data compression techniques. These techniques provide a basis for efficiently dealing with both structural queries and valuebased predicates. We evaluate the effectiveness of such a scheme, presenting results and performance measures that show advantages of using such structures

Methods and study characteristics in the Systematic Rapid Evidence Assessment: Interventions to improve the co-ordination of service delivery for High Cost High Harm Household Units (HCHHHU). TECHNICAL REPORT

This document provides a detailed account of the methods used in the SREA and a detailed summary of the characteristics of the studies included in the SREA. The results are contained in a separate report:- Newman M, Bangpan M, Brunton J, Tripney J, Williams T, Thieba A, Lorence T, Fletcher A, Bazan C (2007) Interventions to improve the co-ordination of service delivery for High Cost High Harm Household Units (HCHHHU). A systematic rapid evidence assessment. London: EPPI-Centre, Social Science Research Unit, Institute of Education, University of London

A new database program installed at the SUERC radiocarbon laboratory

The SUERC Radiocarbon Dating Laboratory has recently replaced its spreadsheet-based record keeping with a new database program, custom designed to help laboratory staff manage the high throughput of nearly 5000 cathodes in the past year. The system can accept data from a variety of sources in addition to manual entry; experimental results can be uploaded from spreadsheets, while integration with graphitisation lines means that graphite yields are automatically recorded. The system is able to pass radiocarbon results directly to OxCal 4 for calibration, with the resulting plots incorporated into the dating certificates issued to submitters. There are also benefits to submitters, with electronic sample submission both eliminating transcription errors and speeding up the logging-in process which keeps turnaround times down. For bone samples, data on collagen yields are now stored electronically and are more readily obtainable from the laboratory. The new SUERC Radiocarbon Dating Laboratory database will make a significant contribution to maintaining the high quality of results produced by the laboratory, aiding staff in tracking sample progress and monitoring quality assurance (QA) samples going through the laboratory, eliminating transcription errors and making communication easier between laboratory staff and sample submitters

Efficient data representation for XML in peer-based systems

Purpose - New directions in the provision of end-user computing experiences mean that the best way to share data between small mobile computing devices needs to be determined. Partitioning large structures so that they can be shared efficiently provides a basis for data-intensive applications on such platforms. The partitioned structure can be compressed using dictionary-based approaches and then directly queried without firstly decompressing the whole structure. Design/methodology/approach - The paper describes an architecture for partitioning XML into structural and dictionary elements and the subsequent manipulation of the dictionary elements to make the best use of available space. Findings - The results indicate that considerable savings are available by removing duplicate dictionaries. The paper also identifies the most effective strategy for defining dictionary scope. Research limitations/implications - This evaluation is based on a range of benchmark XML structures and the approach to minimising dictionary size shows benefit in the majority of these. Where structures are small and regular, the benefits of efficient dictionary representation are lost. The authors' future research now focuses on heuristics for further partitioning of structural elements. Practical implications - Mobile applications that need access to large data collections will benefit from the findings of this research. Traditional client/server architectures are not suited to dealing with high volume demands from a multitude of small mobile devices. Peer data sharing provides a more scalable solution and the experiments that the paper describes demonstrate the most effective way of sharing data in this context. Social implications - Many services are available via smartphone devices but users are wary of exploiting the full potential because of the need to conserve battery power. The approach mitigates this challenge and consequently expands the potential for users to benefit from mobile information systems. This will have impact in areas such as advertising, entertainment and education but will depend on the acceptability of file sharing being extended from the desktop to the mobile environment. Originality/value - The original work characterises the most effective way of sharing large data sets between small mobile devices. This will save battery power on devices such as smartphones, thus providing benefits to users of such devices

Rapid reviews as an emerging approach to evidence synthesis in education

Rapid reviews using abbreviated systematic review methods are of increasing importance for evidence-informed decision-making in education, although there is little guidance about the most suitable approach. Three recently completed rapid review reports are compared to inform discussions on the utility of this type of review in education and to highlight appropriate methods for producing evidence syntheses in a limited time frame. Rapid review methods need to be chosen to fit the needs of the review, which involves: thinking broadly about different kinds of team experience and expertise; estimating the size and nature of the literature to be reviewed; considering the review purpose and nature of the topic; choosing an appropriate synthesis method for the review purpose, evidence base and reviewers’ expertise; fully describing the review approach, and discussing the potential limitations of chosen methods; and understanding the anticipated audiences and tailoring outputs accordingly. Rapid reviews to address urgent and high-priority questions provide the benefits of timeliness and reduced resource requirements. However, it is crucial to understand caveats and limitations to the rapid conduct of evidence syntheses for decision-making purposes. This article offers guidance to support researchers, postgraduate students and commissioners who wish to conduct rapid reviews in a transparent and systematic way, addressing complex questions of relevance to evidence-informed decision-making in education

Systematic reviews for policy

The authors argue that learning from existing evidence is a key skill both for researchers and policy makers. However, how do you go about accomplishing this? What are the key approaches, and how do you make the right choices? Additionally, what are the common pitfalls? This chapter gives the reader a guide to best practice in systematic reviews

Sharing large data collections between mobile peers

New directions in the provision of end-user computing experiences mean that we need to determine the best way to share data between small mobile computing devices. Partitioning large structures so that they can be shared efficiently provides a basis for data-intensive applications on such platforms. In conjunction with such an approach, dictionary-based compression techniques provide additional benefits and help to prolong battery life

Updating the CASE database: analysis of original approach

The CASE database of research evidence is a unique and comprehensive resource for those working in the field of culture and sport. The database currently holds the records of over 5,500 studies on the drivers, impact and value of engagement in culture and sport. In order to maintain the value of the CASE database, a strategy will be needed to regularly update the database. The update strategy should be informed by the knowledge and experience gained from the search and selection process initially used to populate the CASE database. This paper analyses the original search strategy carried out by the EPPI-Centre to aid and inform the development of the update strategy