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)     

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)     

Context effects in performance appraisal: A methodological critique and empirical study.

The standard design used in research on assimilation and contrast effects in performance appraisal suffers from methodological flaws that preclude unambiguous interpretation of experimental results. This standard design is compared with two other designs that provide more appropriate tests of context effects (D. A. Kravitz and W. K. Balzer, 1990). 123 undergraduates rated a videotaped lecture of average quality after rating (1) 2 videotapes depicting good lectures, (2) 2 videotapes depicting poor lectures, or (3) no other videotapes. Half the Ss had rated the target videotape 1 wk earlier. Analyses of the standard design implied contrast effects. Analyses of the alternative designs revealed problems with the positive context manipulation, assimilation effects in the positive context, contrast effects in the negative context, and pretest effects. It is recommended that the standard design not be used. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Single-case designs and clinical biofeedback experimentation

Rigorous evaluation of the effects of biofeedback with clinical populations is necessary, but practical problems often preclude utilization of between-groups experimental designs involving large numbers of clients with clinically relevant problems. Single-case experimental designs provide a viable alternative for answering most research questions. In addition, single-case designs possess several distinct advantages for biofeedback research, including a focus on clinical significance, the use of variability as data not error, unique procedures for establishing generality of findings, and an ability to deal with ethical concerns in clinical research. Basic procedures in the use of single-case experimental designs are described and illustrations in clinical biofeedback research are provided.     

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)     

"The very best of the millennium": Longitudinal research and the demand-control-(support) model.

This study addressed the methodological quality of longitudinal research examining R. Karasek and T. Theorell's (1990) demand-control-(support) model and reviewed the results of the best of this research. Five criteria for evaluating methodological quality were used: type of design, length of time lags, quality of measures, method of analysis, and nonresponse analysis. These criteria were applied to 45 longitudinal studies, of which 19 (42%) obtained acceptable scores on all criteria. These high-quality studies provided only modest support for the hypothesis that especially the combination of high demands and low control results in high job strain. However, good evidence was found for lagged causal effects of work characteristics, especially for self-reported health or well-being outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Therapeutic assessment for preadolescent boys with oppositional defiant disorder: A replicated single-case time-series design.

The Therapeutic Assessment (TA) model is a relatively new treatment approach that fuses assessment and psychotherapy. The study examines the efficacy of this model with preadolescent boys with oppositional defiant disorder and their families. A replicated single-case time-series design with daily measures is used to assess the effects of TA and to track the process of change as it unfolds. All 3 families benefitted from participation in TA across multiple domains of functioning, but the way in which change unfolded was unique for each family. These findings are substantiated by the Behavior Assessment System for Children (Reynolds & Kamphaus, 2004). The TA model is shown to be an effective treatment for preadolescent boys with oppositional defiant disorder and their families. Further, the time-series design of this study illustrated how this empirically grounded case-based methodology reveals when and how change unfolds during treatment in a way that is usually not possible with other research designs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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)     

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)     

Controlling baseline trend in single-case research.

School psychologists commonly conduct interventions for individual students and evaluate their success through single-case research designs, most of which include a baseline observation period. However, concluding intervention effectiveness from a single-case design is problematic when pronounced baseline trend is evident. With positive baseline trend, interpretation of the measured mean difference between phases is ambiguous, and an invalid interpretation is probable. Although an adequate method for controlling baseline trend exists, it is rarely applied in published studies. This article seeks wider application of baseline trend control by describing a modified technique that blends more easily with visual analysis. A second goal of this article is to encourage better informed use of baseline trend control, by empirically demonstrating its need in published studies, and its impact on R2 effect sizes and on autocorrelation. Finally, baseline trend control is combined with elimination of autocorrelation, for results that can withstand the scrutiny of the broader research community. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Introduction to the special section on adult survivors of childhood sexual abuse.

Sexual abuse researchers need to use more complex models of abuse and more sophisticated research designs for studying long-term effects and for evaluating treatment programs. The articles that comprise this special section integrate the study of sexual abuse with perspectives on adult victimization, developmental psychopathology, and attachment theory and also offer specific methodological suggestions for improving research on long-term effects and therapy with the abuse survivor. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Quality assurance programme for nursing

This article describes a conceptual and methodological framework for evaluating nursing care quality. The conceptual framework is based on Orem's theory of self-care which emphasizes the importance of decisions in the selection of nursing process based on patient status and problems. The primary outcome criteria is self-care. The methodological framework is based on Greenfield's criteria maps methodology for linking patient status (problems or diagnoses) to decisions about nursing interventions and linking these specific nursing intervention criteria to desired outcomes for self-care. The article further describes a multiagency quality assurance programme for nursing. The programme includes: a definition of criteria and standards across agencies; nursing care management protocols that define standards of care; continuing education courses for nursing based on management protocols; the maps method of auditing actual and recorded nursing process and patient outcomes as defined in the management protocol.     

Utilization of the simultaneous treatment design to improve student behavior in a first-grade classroom.

Presents a brief discussion of time-series designs and outlines the methodological limitations of the ABAB design, one of the most representative and widely used time series. The simultaneous treatment design is discussed as one means to avoid the serious limitations of the ABAB. A single case study is presented to demonstrate the utility of the simultaneous treatment design to modify the behavior of a 1st-grade male. One teacher and her aide recorded data and administered the program. The simultaneous treatment design allowed for statistical comparison of the treatment effects of 2 contingency programs administered simultaneously. The more effective program was successfully maintained. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Theory and method in cross-cultural psychology.

Cross-cultural psychology is considered as a methodological strategy, as a means of evaluating hypotheses of unicultural origin with evidence of more panhuman relevance, and as a means of developing new theoretical accounts of psychological phenomena that profit from broad sampling of human populations and social situations. As a methodological strategy, difficulties arise from the necessity of the quasi-experimental, comparative research design and from ignorance of the "minds" of Ss. It is argued that the bases of solutions to these methodological difficulties lie in the theory, much of which is available in the psychological literature. One form of theory that promises to be important provides abstract explanatory concepts requiring concrete specification in any particular investigation or application. Examples are discussed, including variants of utility theory and other approaches sharing similar characteristics. The importance of utilizing available psychological theory in the analysis of methodological approaches to cross-cultural study is emphasized. (46 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Studying the effectiveness of psychotherapy: How well can clinical trials do the job?

Although there has been much discussion of the recent Consumer Reports (CR) study (1995) on the effectiveness of psychotherapy, there is little new information reported either in the CR article or in M. E. P. Seligman's (1995) discussion of the findings. The findings that are new are hard to interpret because of serious methodological problems. In fact, the CR study is similar in many ways to H. J. Eysenck's (1952) controversial report on the effectiveness of psychotherapy, a study that has been rejected by the field despite the fact that it avoided some of the methodological shortcomings of the CR study. It would be a mistake to put forth a design rejected in the 1950s as an exemplar of good effectiveness research, especially when better alternatives exist. Clinical trials, despite many limitations, can answer all of the questions posed by M. E. P. Seligman, without the interpretive ambiguities and other methodological problems inherent in surveys such as the one published in CR . (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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)     

Methodological errors in marital and child treatment research.

Discusses common methodological errors in child and marital treatment research and presents suggestions to help investigators avoid such errors. The following areas are covered: selection of Ss and therapists, scope and source of dependent measures, treatment specification, experimental design, and data analysis and interpretation. Some of the most salient errors include (a) unsubstantiated diagnoses or client labels; (b) very few therapists per treatment condition; (c) restricted outcome criteria and the lack of reliable, valid dependent measures; (d) failure to provide treatment manuals and to check empirically whether the treatments were actually implemented; and (e) experimental designs that fail to address issues such as maturation, expectation, nonspecific relationship factors, and practical significance. (56 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A paradigm for single-case research: The time series study of a long-term psychotherapy for depression.

Articulates a paradigm for single-case research in psychotherapy. A patient diagnosed as having major depressive disorder was seen in an intensive, twice-weekly psychodynamic psychotherapy for 2.5 years. Each session was videotaped, and assessments of patient change were obtained at regular intervals. A time-series analysis was used to model fluctuations in the therapy process to take into account time and the effect of previous events on subsequent changes, thereby preserving the context-determined meaning for therapist and patient actions. A bidirectional analysis of causal effects shows that the influence processes between therapist and patient are mutual and reciprocal and suggests that the effect of the patient on the therapist and on the process has not been made sufficiently explicit in previous models of process and change. The potential of intensive single-case designs for uncovering causal effects in psychotherapy is demonstrated. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modelling and design of cross-over trials

There are many diseases and conditions that can be studied using a cross-over clinical trial, where the subjects receive sequences of treatments. The treatments are then compared using the repeated measurements taken 'within' subjects. The actual plan or design of the trial is usually obtained by consulting a published table of designs or by applying relatively simple rules such as using all possible permutations of the treatments. However, there is a danger is this approach because the model assumed for the data when the tables or rules were constructed may not be appropriate for the new trial being planned. Also, there may be restrictions in the new trial on the number of treatment sequences that can be used or on the number of periods of treatment particular subjects can be given. Such restrictions may mean that a published design of the ideal size cannot be found unless compromises are made. A better approach is to make the design satisfy the objectives of the trial rather than vice versa. In this paper we describe an approach to constructing such tailor-made designs which we hope will lead to ill-fitting 'off the peg' designs being a thing of the past. We use a computer algorithm to search for optimal designs and illustrate it using a number of examples. The criterion of optimality used in this paper is A-optimality but our approach is not restricted to one particular criterion. The model used in the search for the optimal design is chosen to suit the nature of the trial at hand and as an example a variety of models for three treatments are considered. We also illustrate the construction of designs for the comparison of two active treatments and a placebo where it can be assumed that the carry-over effects of the active treatments are similar. Finally, we illustrate an augmentation of a design that could arise when the objectives of a trial change.