Realist evaluation - promise, problems and practicalities

Realist evaluation is an innovative, multi-method approach to evaluating the effectiveness of complex health care interventions that is having an increasing impact on the research community. Drawing on their experience doing four realist evaluations in diverse areas of healthcare, the authors offer a comprehensive overview and critique of essential theory and practice. The first paper (Realist review and realist evaluation: an introduction) introduces the main components of the approach and shows how realist review can support realist evaluation. The second paper (Concepts and methodology for realist evaluation: help or hindrance?) provides further detail on the key concepts, shows how they can be operationalised, and discusses the advantages and difficulties of using these ideas. Following these two papers introducing and illustrating the major concepts, the third paper (Realist Evaluation: a critical realist critique) takes a step back to re-consider realist evaluation in relation to its critical realist roots, asking whether it leads to evaluators abandoning the attempt to understand (and if necessary challenge) the underlying values of health care interventions and contenting themselves merely with explicating the factors that help or hinder implementation. The fourth and final paper (Data analysis and theory development in realist evaluation) plunges back into the tangled undergrowth of multiple-method data collection and shows how disparate forms of data can be synthesised for theory development, and the results presented in a form that is useful to practitioners and policy-makers.

Wind Power Planning: Problems and Perceptions in Practice and Procedure

Despite the fact that the UK has highest potential in the EU to generate renewable energy from wind, it lags behind its European partners. The departure point for this study is provided by the fact that the land use planning system has been perceived by some to create difficulties in pursuit of the achievement of National Action Plan targets. In the course of a review of literature, legislation, policy and case files a number of issues emerge relating not only to operational practice but structural concerns regarding knowledge, legitimacy and ethics. These are scrutinised in an empirical investigation which provides insights into the ontologies behind how knowledge is used and abused. Concerns are highlighted regarding the tactical manipulation of knowledges and the difficulties associated with objectifying evidence so that it can be understood, validated and authenticated. The paper concludes by reflecting on the implications for the regulatory framework, the legitimisation of decisions and the ethics of the profession and how these, in turn, are conditioned by the production, use and transparency of planning knowledge.

The Holocene vegetation cover of Britain and Ireland: overcoming problems of scale and discerning patterns of openness

The vegetation of Europe has undergone substantial changes during the course of the Holocene epoch, resulting from range expansion of plants following climate amelioration, competition between taxa and disturbance through anthropogenic activities. Much of the detail of this pattern is understood from
decades of pollen analytical work across Europe, and this understanding has been used to address questions relating to vegetation-climate feedback, biogeography and human impact. Recent advances in modelling the relationship between pollen and vegetation now make it possible to transform pollen
proportions into estimates of vegetation cover at both regional and local spatial scales, using the Landscape Reconstruction Algorithm (LRA), i.e. the REVEALS (Regional Estimates of VEgetation Abundance from Large Sites) and the LOVE (LOcal VEgetation) models. This paper presents the compilation and analysis of 73 pollen stratigraphies from the British Isles, to assess the application of the LRA and describe the pattern of landscape/woodland openness (i.e. the cover of low herb and bushy vegetation) through the Holocene. The results show that multiple small sites can be used as an effective replacement for a single large site for the reconstruction of regional vegetation cover. The REVEALS vegetation estimates imply that the British Isles had a greater degree of landscape/woodland openness at the regional scale than areas on the European mainland. There is considerable spatial bias in the British Isles dataset towards wetland areas and uplands, which may explain higher estimates of landscape openness compared with Europe. Where multiple estimates of regional vegetation are available from within the same region inter-regional differences are greater than intra-regional differences, supporting the use of the REVEALS model to the estimation of regional vegetation from pollen data.

Dry computational approaches for wet medical problems

This is a report on the 4th international conference in 'Quantitative Biology and Bioinformatics in Modern Medicine' held in Belfast (UK), 19-20 September 2013. The aim of the conference was to bring together leading experts from a variety of different areas that are key for Systems Medicine to exchange novel findings and promote interdisciplinary ideas and collaborations.

Distal volcanic ash layers in the Lateglacial Interstadial (GI-1): problems of stratigraphic discrimination

A new Icelandic ash layer has been detected in mid-Interstadial sediments in a number of Scottish Lateglacial sequences and has been named the Penifiler Tephra. It is rhyolitic in composition and possesses a chemistry, which is similar to the Borrobol Tephra of early Lateglacial Interstadial age, which also occurs in a number of these same sequences. Where the Borrobol Tephra has been identified in these sequences it consistently exhibits a diffuse distribution accompanied in some cases by stratigraphic bimodality. A number of sedimentological and taphonomic factors are considered in order to account for this distribution. One possibility is that these distributions are produced by taphonomic factors. Another possibility is that the Borrobol Tephra may not be the product of a single Icelandic eruption, but of two events closely spaced in time. In at least two of the sequences investigated in this study, basaltic shards were found in association with the Penifiler and Borrobol tephras, suggesting either a basaltic phase associated with these eruptions, or coincident eruptions from a separate basaltic volcanic centre. The discovery of the new Penifiler Tephra makes a contribution to the regional tephrostratigraphic framework, and provides an additional isochron for assessing the synchroneity of palaeoenvironmental changes during the Interstadial. The true stratigraphic nature and age of the Borrobol Tephra, however, remains unresolved and, therefore, its use as an isochron is more problematic. The possible occurrence of basaltic populations may strengthen correlations with basaltic tephras recently detected in the NGRIP ice-core.

Pitfalls in Protection: How Theory Can Enrich Our Understanding of Regulatory Compliance Problems in Planning Practice

This paper responds to demands for greater academic investigation into environmental protection, specifically the practical and structural problems which underpin regulatory compliance in the planning system. It critiques traditional theories of regulation and answers calls for the development of a thematic lens to facilitate the scrutiny of not only operational practice, but also the broader institutional regime. An empirical investigation builds upon the construct of really responsive regulation to study planning control and it becomes apparent that not only are there significant procedural planning difficulties facing regulatory compliance, but also that a much wider raft of issues must be considered if the complex equation is to be solved. The findings demonstrate how theory can be applied to enrich our rudimentary understanding of deep-seated problems and foster insights into areas of structural importance which are relevant to both planning and the wider regulatory arena.

Solving Decision Problems with Limited Information

We present a new algorithm for exactly solving decision-making problems represented as an influence diagram. We do not require the usual assumptions of no forgetting and regularity, which allows us to solve problems with limited information. The algorithm, which implements a sophisticated variable elimination procedure, is empirically shown to outperform a state-of-the-art algorithm in randomly generated problems of up to 150 variables and 10^64 strategies.

Semi-Qualitative Probabilistic Networks in Computer Vision Problems

This paper explores the application of semi-qualitative probabilistic networks (SQPNs) that combine numeric and qualitative information to computer vision problems. Our version of SQPN allows qualitative influences and imprecise probability measures using intervals. We describe an Imprecise Dirichlet model for parameter learning and an iterative algorithm for evaluating posterior probabilities, maximum a posteriori and most probable explanations. Experiments on facial expression recognition and image segmentation problems are performed using real data.

The destruction of 2-methylisoborneol and geosmin using titanium dioxide photocatalysis

Geosmin (GSM) and 2-methylisoborneol (MIB) are semi-volatile compounds produced by cyanobacteria in surface waters. These compounds present problems to the drinking water industry and in aquaculture because they can taint water and fish producing an earthy-musty flavour. This paper presents an initial study on the use of TiO₂ photocatalysis for the destruction of these compounds in water. The process proved effective with the complete destruction of MIB and GSM being achieved within 60 min. These results suggest that TiO₂ photocatalysis will be a successful method for removal of taint compounds from potable water supplies and fish farms.