Single-Case Evaluation by Social Workers

Mansoor A.F. Kazi

• Publisher: Taylor & Francis
• Year: 2019
• Print ISBN: 9781138346376
• eBook ISBN: 9780429793578
• Edition: 1
• Topic: Ciencias sociales
• Subtopic: Trabajo social

First published in 1998, this is the first definitive text on single-case evaluation in Britain. This is a method of evaluation research which enables progress to be determined by comparing different phases in the life of a single client, group or system. It can also determine the extent to which the social worker's intervention was responsible for the changes in the client's target problem. Examples are provided from British experience.

1 Introduction

This book is concerned with the utility of single-case evaluation in social work, and the experience of applying this methodology in practice. Its main purpose is to demonstrate the viability of single-case designs as a research method in addressing particular questions of evaluation in social work practice. This is achieved mainly through examples of studies involving extensive use of this methodology in British social work. Against a background in which more is written about single-case designs than its actual use in practice, this text concentrates on the application of this methodology to practice and the approaches that have been used to successfully encourage social work practitioners to use single-case designs.

This text explores the requirements of single-case evaluation and its utility for social workers, drawing on the experience of its application in a number of evaluation research projects conducted by the author under the auspices of the Centre for Evaluation Studies at the University of Huddersfield (Kazi 1996). In social work practice, a common evaluation question is whether the services provided are having the desired impact on clients. This was the central question in all the evaluation studies analysed in this book, in a number of settings including social work with school children, social care programmes for the rehabilitation of older people, and probation work with adult offenders. A number of projects reported in this text used single-case evaluation together with other evaluation research methods, including both quantitative and qualitative approaches, to address this question.

Definitions and origins

The two key terms used in this book are assumed to have the same meaning as in Robinson, Bronson and Blythe (1988). Single-case evaluation refers to the use of single-case designs by practitioners to evaluate client progress or the effectiveness of a system. Single-case design refers to a specific research methodology designed for systematic study of a single client or system. Various terms are used to describe this methodology, e.g. idiographic research, single-organism research, nomothetic research, single-case design, single-subject design, intra-subject replication design, and single-system designs. According to Kazdin, the term ‘single-case design’ draws attention to this methodology’s unique capacity to experiment with individual subjects, and it is the widest used (Kazdin 1982, p.3). The term most commonly used in British social work is single-case experimental designs (Sheldon, 1983; Cheetham et al. 1992); however, this term is slightly inaccurate as only some of these designs can be considered to be experimental or explanatory. Therefore, the term used in this text is single-case designs, as in Robinson, Bronson and Blythe (1988).

Barlow & Hersen (1984) trace the origins of single-case designs to physiological studies in the 1830s. Contemporary single-case research can be traced to the work of B.F. Skinner who developed animal laboratory research to elaborate operant conditioning (Skinner 1974, Krishef 1991). However, despite its origins, single-case research has developed in its own right as a methodology that extends beyond any particular view about behaviour (Kazdin 1982). According to Thyer (1993), these designs are ‘currently used by practitioners who hold a variety of theoretical orientations, but the methodology is firmly grounded in the quantitative, positivistic approach to research’ (p.95). It is used in many areas of research including psychology, psychiatry, education and social work. Various texts have been published in the last two decades describing the application of single-case research, e.g. Sheldon 1982b, Tawny & Gast 1984, Kratochwill 1978, Krishef 1991, and Bloom, Fischer & Orme 1995. In British social work, Brian Sheldon was the single author responsible for introducing and advocating the use of this methodology (Sheldon 1983, 1984a, 1986, 1987).

Bloom, Fischer & Orme (1995) define single-case designs as ‘a set of empirical procedures used to observe changes in an identified target (a specified problem or objective of the client) that is measured repeatedly over time’ (p. 5). Data collected across time enables both the worker and the client to examine the client's response to intervention. Nelsen (1988) also states that the basic component of single-case research is repeated objective measurement of the client's target problem. The target problem must be clearly defined and objectively measurable. Case objectives are set and translated into the client's target problem. According to Nelsen (1988, p.366),

...the practice or research hypothesis being tested is that the use of the particular treatment intervention (independent variable) will be followed by a desired change in the client's target problem (dependent variable). The resulting study could be considered explanatory depending on how clearly such a relationship can be demonstrated.

Where possible, data is collected prior to intervention to provide a baseline indication of the problem, and then one or more interventions are implemented. Comparisons between the non-intervention and intervention phases may enable a causal connection to be made between the intervention and its effects. However, the samples used tend to be small, and extraneous influences can only be controlled with less confidence than randomised controlled group trials. Viewed in this way, single-case designs tend to be pre-experimental; at best, where repeated withdrawal designs or multiple-baselines are used across a number of independent subjects, single-case designs could be regarded as quasiexperimental, provided there are sufficient numbers of subjects to enable a reasonable degree of attributable confidence.

The search for practice evaluation methodology

The origins of this book lie in the growing demand from the 1980s onwards for social workers to demonstrate the worth and value of their practice to both the service users and the employers. The author began practising as a social worker in Rochdale’s Education Welfare Service, a social work agency within an education setting, in 1981 and became the agency’s manager in 1987. In an environment of cutbacks in the budgets of local authorities, and the growing role of schools in the decision-making process with the devolution of school budgets, education social workers (i.e., social workers in an education setting) were required to evaluate their practice and demonstrate their effectiveness. As the service provision consisted of direct work by individual social workers with school pupils, their families, and their schools to improve their attendance and functioning within schools, the author began to search for an evaluation system that could be readily applied to social work practice and which enabled the systematic tracking of progress made by individual service users.

A literature search in the late 1980s indicated that there was an evaluation research methodology which claimed to offer appropriate strategies for social workers seeking to evaluate their practice with service users. The introduction of single-case evaluation was described as a ‘social work revolution’ in America (Fischer 1981, p. 199). It was argued that a research methodology that could be built into practice was now available to social workers, and that the use of this methodology in a systematic tracking of client progress would enhance practice. Several texts describing this methodology were available, almost entirely originating in North America. However, it became apparent that there were very few examples of the extensive use of this methodology from North America, and none within the United Kingdom. In the UK, Sheldon had written about this methodology, and provided a few examples of its use. However, the prevalent thinking in academic circles (as indicated from the pages of British Journal of Social Work) was that this methodology had some serious flaws because of its positivist origins, and therefore it could not be applied in social work.

In 1991, the author joined the academic staff within the University of Huddersfield, and found that there were other social work agencies also searching for appropriate ways of evaluating practice. Kirklees Education Social Work Service, a social work agency within an education setting in Yorkshire, was the first to work with the author to apply single-case evaluation on an extensive, agency-wide basis. This evaluation research was reported in 1993 and is described in Chapter 3. In a letter to the author and the agency’s social workers, Bruce Thyer (editor of Research on Social Work Practice) acknowledged that this effort was one of the most extensive of its kind on either side of the Atlantic. In Britain, this became the first major study reporting on an extensive use of single-case designs (Kazi 1996a, Kazi & Wilson 1996). The Centre for Evaluation Studies was formed in the wake of this study, and more and more social workers and health workers from various settings began to use single-case evaluation. Learning from the experience of the first effort, the author used similar strategies with other agencies and found that, following some initial training and ongoing consultation, and with the participation of their managers, social workers, health workers and probation officers were ready and willing to use single-case designs to evaluate their practice.

Single-case evaluation (or the use of single-case designs in evaluating practice) is firmly rooted in the empirical practice movement which began to develop in social work research mainly in the 1980s, claiming to provide practising social workers with the means to evaluate their own practice. Back in 1981, Joel Fischer referred to the development of single-case evaluation as the ‘social work revolution’. He argued, ‘a research technology that can be built into practice and can serve a number of functions that will enhance practice is now available to social workers. In and of itself, this development may be the highlight of—and certainly is a key to—the revolution in practice’ (Fischer, 1981, p. 201). However, by the end of the decade it became clear that this ‘revolution’ had directly affected only a small part of social work. In Britain, for example, apart from Sheldon's work, the only report to date in British Journal of Social Work of a study using singlecase designs is in fact American (Bentley, 1990). Sheldon’s writings in the 1970s and 1980s introduced this methodology to British social work and provided some examples of its use. However, up to December 1995, there were no published studies in the British or North American professional and academic press that involved extensive use of this methodology in British social work.

In hindsight, it could be said that the earlier claims regarding this methodology were somewhat overstated, and this in part explains why this ‘revolution’ did not materialise. In this author’s view, there are also two further reasons why single-case evaluation did not seem to take off as it was hoped in the 1980s. First, the earlier definitions tended to emphasise experimental designs which would not only track client progress, but also attempt to provide a causal link between client progress and the social work intervention used. Such designs involved a systematic introduction and withdrawal of interventions to test their effects (Sheldon 1988, Thyer 1993) and were seen by many social workers as unsuitable to the needs of their practice. Second, based on this earlier emphasis, the introduction of single-case designs in social work research came under fierce opposition as part of the epistemological debate between those who favoured the positivist approach (which included single-case designs) and those who favoured the naturalistic or qualitative approach. For example, it was argued that this type of evaluative research was incompatible with most social work practice, and that the use of measures in single-case designs was reductionist and incapable of representing the reality of most social phenomena.

This book attempts to redress this situation by reporting on a number of recent experiences which involve extensive use of single-case evaluation in this country (Kazi 1996, 1996a; Kazi & Wilson 1996). It draws on the experience of social workers (and workers in allied professions) in a number of settings and agencies in Britain to assess the utility of this methodology in practice. Chapter 3 reports on an agencywide attempt to apply single-case evaluation procedures in Kirklees Education Social Work Service, and Chapter 4 describes a similar project with students on placement with West Yorkshire Probation Service. Chapter 5 reports on the experience of applying this methodology in combination with other methods to evaluate the effectiveness of community care projects for older people. Single-case designs are used to systematically track client progress and the aggregation of this data is combined with the data from other methods (using both quantitative and qualitative approaches) to provide some indications of the projects’ effectiveness.

Shifts in requirements of methodological rigour

In the author’s work with education social workers in Kirklees (Chapter 3), the earlier attempts emphasised the use of measures with proven reliability (e.g. in Corcoran & Fischer 1987), and a search for causal links to be established between the intervention and its effects. However, on the basis of the earlier experience, the strategy was changed to concentrate on the specification and measurement of target problems, whilst allowing the designs to fall into place naturally according to the needs of practice. The aim was to repeatedly track client progress, not to attribute a causal link between the programme and the progress made by the client. By this time, the definition of single-case evaluation no longer emphasised measures of proven high reliability or the need to establish a causal link. For example, the Encyclopaedia of Social Work (Blythe 1995, p. 2164) describes single-case design as

a research methodology that allows a social work practitioner to track systematically his or her progress with a client or client unit. With increasingly rigorous applications of this methodology, practitioners can also gain knowledge about effective social work interventions, although this is a less common goal.

In other words, a common emphasis is on continuous assessment over time to track client progress, and not on attempting to determine a causal link between such progress and the social work intervention. The basic hypothesis addressed is that a social work programme will lead to client progress—and not necessarily that the programme would cause the changes to happen. Therefore, control of alternative explanations is not sought after. Nevertheless, systematic tracking of client progress would enable both the practitioner and the client to evaluate, on a regular basis, whether the desired objectives of the social work intervention were being achieved or not, and the extent to which they were being achieved.

With this limited purpose in mind, the only fundamental requirement of this methodology is the measurement of the client’s target problem repeatedly over time, using an appropriate indicator of progress which is made as reliable as possible. The practitioner is required to select an outcome measure that best reflects changes in the client’s condition, and then to apply the same measure repeatedly over a period of time. The initiation and withdrawal of social work interventions is determined in all cases by the needs of practice, and not the demands of the research programme. The resulting data will enable the systematic tracking of client progress in the period when repeated measurement takes place. The emphasis on measures of proven high reliability has also shifted, and practitioners are encouraged to develop and to use a variety of measures appropriate to the needs of their practice, provided that they attempt to minimise potential errors and thereby maximise reliability as far as possible.

The author’s work to promote the use of single-case evaluation by social work practitioners in a variety of settings has been reported elsewhere (Kazi & Wilson 1996; Kazi, Mantysaari, & Rostila 1997). This apparent willingness of social work practitioners to use single-case evaluation is due to three main developments: 1) changes in the requirements of the methodology which enable an improved response to the needs of practice; 2) the emergence of a pragmatic approach of mixing methods in order to compensate for the limitations of any single method; and 3) the building of a partnership between academic researchers and social workers to evaluate practice. However, these developments led to the realisation that, in the explanation of the effectiveness of programmes, single-case evaluation could only provide a limited account, and that it was desirable to combine this methodology with other methods to describe reality in a more comprehensive and meaningful way. The exact way in which the methodology was applied, and the selection of the effectiveness questions that needed to be addressed, was dependent upon the needs of practice as well as the theoretical orientations of the inquirer.

Contemporary developments in practice evaluation

The demands on social work and other related professions to demonstrate effectiveness have continued to grow in the last two decades. The pressures from changes in the legal and societal context mean that social work is no longer taken for granted and that its worth has to be demonstrated (Parton 1994). The Children Act 1989, and the NHS and Community Care Act 1990, both included requirements for planning in response to need, and reviewing progress. The purchaser- provider split, the growth of the voluntary and private sectors alongside the public sector, and the introduction of competition for contracts have also made monitoring and evaluation more central. The resources are finite, and yet the social needs are complex and in a state of flux. Effectiveness research is one way to make social programmes accountable and to enable politicians, agencies and practitioners to make hard choices in the allocation of scarce resources.

The analysis thus far has concentrated on demonstrating the worth of social work. There is another dimension to this—the need to develop and improve the content of social work practice itself, so that it is better able to meet the needs of its clients and the wider society. The two main purposes of effectiveness research are providing evidence of the worth of social work practice, and striving to improve practice itself to respond to the changing needs and contexts. Whether emphasis is placed on one or the other of these purposes depends on the perspective of the inquirer.

In response to these pressures and developments in the philosophies of science, there has been a growth in research methods textbooks and other publications addressing the need for social work to demonstrate its effectiveness. Most of the authors have tended to be university based, but these publications also reflect a developing partnership between academics and social work practitioners. For example, Macdonald (1996) is one of a number of publications on effectiveness from Bamardos—a children’s charity and a voluntary social work age...

Table of contents

• Cover
• Half Title
• Dedication
• Title Page
• Copyright Page
• Table of Contents
• List of Figures
• List of Tables
• Series Editors' Preface
• Acknowledgements
• 1 Introduction
• 2 Single-Case Evaluation Strategies
• 3 Examples of Research in Education Social Work
• 4 Examples of Research in a Probation Service
• 5 Examples from Adult Rehabilitation
• 6 Advantages and Limitations of Single-Case Evaluation
• 7 Contemporary Perspectives in Effectiveness Research
• Bibliography
• Index