Single-case design: A primer for play therapists.

Play therapy research is typically presented to practitioners as extensive and detailed studies that involve excessive controls of variables and large numbers of subjects in order to generalize findings. However, single-case design is one research design that involves concentration on data collection from few participants and involves clinical decision-making of the play therapist. This article defines single-case design and provides step-by-step suggestions for how to conduct a single-case design study. We also provide a specific example of single-case application to play therapy intervention and further discuss common problems in play therapy single-case design implementation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of autocorrelation on the results of visually analyzing data from single-subject designs

OBJECTIVE: Single-subject research designs are used to conduct clinical research and outcome evaluation in occupational therapy. Confusion exists regarding the best method to analyze and interpret single-subject data. METHOD: One hundred graphs displaying the results of published single-subject research were examined to determine the influence of autocorrelation on the visual inferences made by the original investigators. The graphs were selected from 20 articles published over 10 years in seven rehabilitation journals. The data were extrapolated and lag 1 autocorrelation coefficients computed for both the baseline and treatment phases. RESULTS: Data analysis focused on two issues: (a) whether a relationship existed between the amount of autocorrelation present in a graph and the conclusion on the basis of visual analysis and (b) whether the amount of autocorrelation varied across different phases of the single-subject graphs. When a significant degree of autocorrelation was present, researchers using visual analysis were more likely to conclude that there was no clinically significant change in performance. Autocorrelation values were significantly higher in the treatment phases of the single-subject designs. CONCLUSION: Additional research is needed to establish a set of decision rules to assist clinicians in using visual analysis to evaluate the results of single-subject research.     

Introduction to special section: Single-case research in psychotherapy.

As a method of inquiry, single-case research has been relegated conventionally to the role of discovery or hypothesis generation. New developments in the methodology of intensive single-case designs has extended its applicability to the testing of clinical theoretical constructs and even the identification of causal relations. A series of articles illustrates newer developments in single-case research and its use in addressing a wide range of clinical and research questions. It has often been noted that psychotherapy research has had little influence on clinical practice. Single-case designs are more closely linked to traditional means of clinical inquiry, teaching, and learning than are large-sample studies, and they are likely to have more immediate relevance for how intervention is conducted. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Single-case methodology in psychotherapy process and outcome research.

Delineates and explains the essential characteristics of single-case research methodology applied within the domain of psychotherapy research. Single-case research is presented as a subclass of intrasubject research in which aggregation across Ss is avoided and the generality of one's findings is addressed through replication on a case-by-case basis. The basic ways in which single-case designs vary are also discussed, and 3 basic types of single-case research are differentiated: (1) single-case experiments, (2) single-case quantitative analyses, and (3) case studies. Furthermore, some of the major weaknesses in current single-case psychotherapy research are identified. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Enhancing the scientific credibility of single-case intervention research: Randomization to the rescue.

In recent years, single-case designs have increasingly been used to establish an empirical basis for evidence-based interventions and techniques in a variety of disciplines, including psychology and education. Although traditional single-case designs have typically not met the criteria for a randomized controlled trial relative to conventional multiple-participant experimental designs, there are procedures that can be adopted to create a randomized experiment in this class of experimental design. Our two major purposes in writing this article were (a) to review the various types of single-case design that have been and can be used in psychological and educational intervention research and (b) to incorporate randomized experimental schemes into these designs, thereby improving them so that investigators can draw more valid conclusions from their research. For each traditional single-case design type reviewed, we provide illustrations of how various forms of randomization can be introduced into the basic design structure. We conclude by recommending that traditional single-case intervention designs be transformed into more scientifically credible randomized single-case intervention designs whenever the research conditions under consideration permit. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The use of single-case methodology in psychotherapy research.

Discusses a new psychotherapy research strategy, the experimental analysis of single cases, which is being increasingly employed in behavior modification studies. The major single-case experimental designs used in these studies include the reversal design, withdrawal design, multiple schedule design, and multiple baseline design. Examples of these designs are presented, and the advantages and disadvantages of each design are critically discussed. Possible merits and limitations of applying controlled single-case methodology to the general area of psychotherapy research are also explored. It is concluded that in spite of limited purposes, single-case experimentation has proved to be a vital source of strength in the development and evaluation of behavior modification, and that it might be equally useful in the experimental study of other psychotherapy approaches. (26 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Single-case research designs: A neglected alternative.

Comments on the article by L. Wilkinson & the Task Force on Statistical Inference (see record 1999-03403-008) which was meant to initiate discussion in the field about changes in current practices of data analysis and reporting. The report was concerned with the use of statistical methods only and is not meant as an assessment of research methods in general. The present article criticizes Wilkinson's article, noting that it lacks any recognition that single-case research design might be an alternative to current practices. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"Generalized single-case randomization tests: Flexible analyses for a variety of situations": Erratum.

Reports an error in "Generalized single-case randomization tests: Flexible analyses for a variety of situations" by Joel R. Levin and Bruce E. Wampold (School Psychology Quarterly, 1999[Spr], Vol 14[1], 59-93). (1) In Table 5 (p. 76), in the cell associated with the third row and third column, the upper value of 18.3 should be 18.73. (2) On p. 81, in the section titled "Simultaneous Start-Point Randomization for Matched Pairs of Units," the sentence beginning in line 10 should read: "With k? acceptable start points for the first pair and k? for the second, there would be k?k? summed sums and null hypothesis-compatible summed differences for the randomization distribution to test Rgen and Rcomp, respectively (as indicated in the Appendix, p. 89)." (The following abstract of the original article appeared in record 1999-10944-004.) A general class of single-case statistical procedures, derived from previously developed nonparametric randomization tests, is presented. These procedures are widely applicable in behavioral and educational research contexts in which only a few experimental "units" (individuals, small groups, or classrooms) are the recipients of one or more experimental treatments or interventions. Specifically illustrated are designs that focus on both the general and comparative effectiveness of alternative interventions (including control/placebo treatments), multiple units with differentiable characteristics (i.e., intervention by unit characteristic interactions), and multiple outcome measures (i.e., intervention by outcome measure interactions). Also provided are operational modifications that enhance the internal validity of studies incorporating single-case randomization-based analyses. Appropriate cautions and issues surrounding the use of these procedures are included. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Coming Full Circle: Using Research and Practice to Address 27 Questions About 360-Degree Feedback Programs.

The research evidence addressing practical issues faced when implementing a 360-degree feedback system are reviewed. Notwithstanding the popularity and apparent utility of 360-degree feedback programs, there is a need for clearer translations of research-based knowledge into recommendations for practically applying such programs. This article uses the published research studies that have been conducted on 360-degree feedback programs to address 27 specific questions that often arise in the development, implementation, administration, and interpretation of multisource feedback programs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Combining Single-Case Experimental Data Using Hierarchical Linear Models.

Although meta-analysis has become a widespread data-analytic strategy to review a collection of group comparison studies, meta-analyses of the results of single-case studies are relatively sparse. In this article it is argued that combining the data of individual cases, studied in different studies or in the same study, can be a meaningful and important source of information. By combining the results of individual cases, both group and individual parameters can be estimated and tested efficiently, using all data available. Moreover, the moderating effect of case or study characteristics can be explored. We (a) describe the hierarchical linear models approach to answer these general meta-analytical questions for single-case data; (b) compare the approach with the Busk and Serlin (1992) approach; (c) present hierarchical linear models that can be used in various situations for the quantitative integration of single-case data; and (d) show how the SAS software can be used for estimating the unknown parameters. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Consider the simple screw: Cognitive science, quality improvement, and psychotherapy.

Psychological therapy based on cognitive science advances as psychological states can be precisely measured. This article describes a treatment approach, personal quality improvement (PQI), that draws on (a) the states of mind (SOM) model, a mathematical model built on cognitive assessment research on the balance of positive and negative thoughts and feelings; (b) total quality control, a method for improving quality as defined by increased system stability by empowering average workers to reduce variability through process monitoring; and (c) the phase model of psychotherapy, a framework that proposes 3 distinct stages of treatment. In a single-case study, a depressed client used PQI to track emotional, self-image, and optimism balance, achieving an improvement trajectory consistent with the SOM and phase models. PQI emphasizes process, uses a patient focused treatment paradigm that provides tools for autonomous functioning, and allows for calibration of psychological measures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Clinical practice as natural laboratory for psychotherapy research: A guide to case-based time-series analysis.

Both researchers and practitioners need to know more about how laboratory treatment protocols translate to real-world practice settings and how clinical innovations can be systematically tested and communicated to a skeptical scientific community. The single-case time-series study is well suited to opening a productive discourse between practice and laboratory. The appeal of case-based time-series studies, with multiple observations both before and after treatment, is that they enrich our design palette by providing the discipline another way to expand its empirical reach to practice settings and its subject matter to the contingencies of individual change. This article is a user's guide to conducting empirically respectable case-based time-series studies in a clinical practice or laboratory setting. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The attrition dilemma: Toward a new strategy for psychotherapy research.

Presents an analysis of the attrition dilemma in psychotherapy research and reviews the methods used to compensate for data loss. It is argued that attrition is not ultimately a problem of bias but a problem of lack of information. A reformulation is offered that integrates single-case studies with traditional group comparison methodology in an attempt to find optimal causal relations of treatments to outcomes. (10 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Methodological and interpretive problems of single-case experimental designs.

Considers methodological and interpretive problems that frequently arise in single-case experiments. These designs are uniquely suited to evaluating treatment effects with individual clients. Although treatment is evaluated by comparing baseline and treatment phases, the manner in which this is accomplished varies as a function of the specific design. Typically, the comparison is replicated over time (ABAB design) or across different behaviors (multiple-baseline design). Several methodological problems frequently arise in single-case designs, such as deciding when to alter phases or conditions in the experiment, ensuring that the intervention is implemented, comparing alternative treatments unconfounded by sequence effects, and ensuring that data are collected reliably. Many interpretive problems of single-case designs stem from the criteria used to evaluate treatment. The ambiguity of these criteria, relative to statistical tests used in group designs, presents unique problems for evaluating treatment. (42 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comment: Integrating methodologies in the scientific study of interpersonal psychotherapy: A reaction to "Therapist immediacy in brief psychotherapy: Case study I and case study II".

In this reaction article, the author concentrates on selected methodological components characterizing both Kasper, Hill, and Kivlighan's (see record 2008-13167-001) and Hill, Sim, Spangler, Stahl, Sullivan, and Teyber's (see record 2008-13167-002) respective case studies of therapist immediacy in brief psychotherapy. In tandem, the foci and methodology of these investigations break new ground in the scientific study of interpersonal psychotherapy, and more generally they serve as paradigmatic illustrations of the form that psychotherapy research can take if it is to be truly more meaningful and useful for practitioners. Emphasis is placed on the investigators' integration of single-case research, elements of change process research, and quantitative and qualitative methods in a way that enables highly intensive examination of this core intervention in interpersonal psychotherapy. Specific elements and implications of each of these methodological components are briefly discussed, which also creates a context for addressing the issue of discovery versus verification as this pertains to the present studies. Some underlying philosophical considerations are also briefly touched on along the way. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Single-case investigative research and its relevance for the nonoperant clinician.

Asserts that a new research approach is needed to intra-S investigations that deals as seriously with actual clinical goals as it does with experimental design criteria. It is contended that the work of M. B. Shapiro published from 1951 to 1979 offers the nonoperant clinician a patient-oriented approach to evaluate the efficacy of clinical treatment. Four of his methodological principles of single-case research are presented. A new therapy process structure, the stage process model, which is compatible with Shapiro's patient-oriented approach, is presented. (34 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comments on "a case study of the process and outcome of time-limited counseling."

The single-case outcome study reported by C. E. Hill et al (see record 1983-10833-001) has several strengths, including the use of sequential analysis and careful recording and investigation of sessions. However, several limitations are identified, such as the small variety of outcome measures, the lack of behavioral change measures, the failure to impose a theoretical structure on the therapy and its evaluation, and the suitability of this client for case analysis. Recommendations are made for case studies in outcome research. (12 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The current state of empirical support for the pharmacological treatment of selective mutism.

This article reviews the current state of evidence for the psychopharmacological treatment of children diagnosed with selective mutism within the context of its link to social anxiety disorder. An increased focus on potential medication treatment for this disorder has resulted from significant monetary and resource limitations in typical practice, parental choice in utilizing treatment from medical personnel, and children who fail to respond to psychosocial interventions. A total of 21 publications within the English literature were located. From these, data for only 57 children between the ages of 4 to 17 years have been reported, with the majority of studies utilizing single-case design or case study methodology. Yet, pharmacological data appear promising for treatment resistant cases of selective mutism. The need for additional research via efficacy/effectiveness methodologies remains. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Integrating psychotherapy research and practice: Modeling the change process.

Identifies factors responsible for the slowness over the years of psychotherapy researchers to utilize intensive analysis procedures. These factors include the uncritical utilization of conventional research methodologies, the failure to distinguish between different types of intensive analysis designs, the assumption that intensive analysis is necessarily unscientific, and the fact that the behavioral single-case experimental design is inappropriate for studying other forms of therapy. The task-analysis approach to psychotherapy research is presented as a methodologically rigorous alternative to the behavioral single-case experimental design. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Response to "All That Glitters Is Not Always Gold: Medical Offset Effects and Managed Behavioral Health Care".

Comments on an article by J. S. Fraser (see record 1996-00461-003) regarding managed behavior health care offset effects in marketing managed behavioral care services. Previous criticism of medical cost offset, problems in Fraser's study and report, and the relationship of research to public accusations against Medco (Fraser's funding source) are discussed. The present author concludes that Fraser's article does not address the stated goal of clarifying unrealistic expectations that led to the Wall Street Journal exposé. All of Biodyne's contractual failures alleged in the Wall Street Journal article remain unchallenged by Fraser's examination of medical cost offset. It is argued that because the published article contains numerous errors, questions must also be raised about the accurate collection and interpretation of raw data. (PsycINFO Database Record (c) 2010 APA, all rights reserved)