The alternating treatment design (ATD) consists of rapid and random or semirandom alteration of two or more conditions such that each has an approximately equal probability of being present during each measurement opportunity.
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How do you design an alternating treatments design?
To implement an alternating treatments design, begin as usual with a brief baseline, simply to ensure that the client actually needs intervention to eat those foods. You then alternate meals back and forth between the two different treatments that you want to evaluate.
What is the what works clearinghouse?
The What Works Clearinghouse (WWC) reviews the existing research on different programs, products, practices, and policies in education. Our goal is to provide educators with the information they need to make evidence-based decisions. We focus on the results from high-quality research to answer the question “What works in education?”
What is the alternating treatment design in abab?
In the alternating treatment design, following a baseline phase, the treatments are alternated in rapid succession (compared to the ABAB design which has more within phase observations or measurements) allowing a comparison of the treatment to baseline or an alternative treatment over repeated observations (e.g., ABABABABAB and ABCBCBCBC).
Can alternating treatment phases be counterbalanced or randomized?
The alternating treatment phases can be counterbalanced or randomized. In each of these designs the researcher must attend to various features of the data, including mean changes among phases, trend, variability, and autocorrelation in the data.
What are the What Works Clearinghouse standards?
The current WWC standards are used to guide the review of studies with acceptable outcomes. This protocol guides the review of research that informs the What Works Clearinghouse (WWC) intervention reports in the Adolescent Literacy topic area.
Why is an ABA design called a reversal design?
1 Reversal or ABAB design. The reversal design demonstrates the effect of the intervention by alternating the presentation and removal of the program over time. The purpose of the design is to demonstrate a functional relationship between the target behavior and the intervention.
What Works Clearinghouse systematic review?
The systematic review is the basis of all What Works Clearinghouse products. Systematic reviews use explicit methods to identify, select, and critically appraise relevant research, and to extract and analyze data from studies.
What does multiple baseline design mean?
an experimental approach in which two or more behaviors are assessed to determine their initial, stable expression (i.e., baseline) and then an intervention or manipulation is applied to one of the behaviors while the others are unaffected.
What is alternating treatment design?
a type of study in which the experimental condition or treatment assigned to the participant changes from session to session or within sessions.
Why is ABAB design better than ABA?
It can seem counterintuitive to withdraw a potentially effective treatment. But with ABAB, the intervention is brought back and is likely to work even more quickly the second time. This means behavior modification is likely to be even stronger than before.
What Works Clearinghouse dyslexia?
The program teaches reading and spelling through multisensory lessons with a strong emphasis on phonemic awareness and alphabetic code knowledge. For students, the Dyslexia Training Program provides 336 one-hour lessons on DVD using two trained dyslexia therapists.
What Works Clearinghouse spelling?
The What Works Clearinghouse (WWC) identified two studies of Spelling Mastery that both fall within the scope of the Students with Learning Disabilities topic area and meet WWC evidence standards. These two studies meet standards without reservations.
What do you know about research intervention?
Intervention research is all about learning what treatments or strategies work best to improve outcomes and making a difference in what matters most to people. A true experiment or randomized controlled trial (RCT) is the strongest type of intervention study for testing cause and effect relationships.
What are the three major types of multiple baseline designs?
Three basic types of multiple baseline design are (a) multiple baseline across different behaviors of the same subject, (b) multiple baseline across the same behavior of different subjects, and (c) multiple baseline of the same behavior of one subject across different settings.
What is an example of a multiple baseline design?
Multiple-Baseline Design Across Settings For example, a baseline might be established for the amount of time a child spends reading during his free time at school and during his free time at home. Then a treatment such as positive attention might be introduced first at school and later at home.
What is multiple treatment design?
Multi-element/alternating treatments design. -Two or more treatments are rapidly alternated; predetermined changes in conditions. -Differences in responding are a function of the stimulus/context. -Similar to the multiple reinforcement schedule used in basic research.
How to implement alternating treatment?
To implement an alternating treatments design, begin as usual with a brief baseline, simply to ensure that the client actually needs intervention to eat those foods. You then alternate meals back and forth between the two different treatments that you want to evaluate.
What is simultaneous treatment?
The same is true for simultaneous-treatment designs; a design that is appropriate for situations where one wishes to evaluate the concurrent or simultaneous application of two or more treatments in a single case. Rapid or random alteration of treatment is not required with simultaneous-treatment design.
How many alterations are required for ATD?
ATD requires a minimum of two alterations per data series.
What is an ATD?
The alternating treatment design (ATD) consists of rapid and random or semirandom alteration of two or more conditions such that each has an approximately equal probability of being present during each measurement opportunity. As an example, it was observed during a clinical training case that a student therapist, during many sessions, would alternate between two conditions: leaning away from the client and becoming cold and predictable when he was uncomfortable, and leaning towards the client and becoming warm and open when feeling comfortable. The client would disclose less when the therapist leaned away, and more when he leaned forward. If it were assumed that the therapist had preplanned the within-session alternations, an ATD as shown in Figure 6 would be obtained. The condition present in the example at any given time of measurement is rapidly alternating. No phase exists; however, if the data in each respective treatment condition are examined separately, the relative level and trend of each condition can be compared between the two data series (hence the name between-series designs).
What is Snyder and Shaw's methodology?
Snyder & Shaw (this volume) provide a substantive discussion of the use of single-case experimental designs (also referred to as “small-n designs”) to answer an assortment of questions about sexuality. Nonetheless, we believe that the use of single-case experimental methodology to answer questions regarding childhood sexuality is of sufficient importance to warrant some discussion here.
What is single case design?
Although usually labeled a quasi-experimental time-series design, single-case research designs are described in this article as a separate form of research design (formerly termed single-subject or N = 1 research) that have a long and influential history in psychology and education (e.g., Kratochwill, 1978; Levin et al., 2003) and can serve as an alternative to using large, aggregate group designs ( Shadish and Rindskopf, 2007 ). Single-case research designs bear similarly to time-series design and have often been regarded as quasi-experimental because they usually do not (but could) include randomization in the experiment. In the single-case design, replication is scheduled to help rule out various threats to validity. Single-case designs can involve a single participant or group as the unit but differ from repeated measures and hierarchical linear modeling (HLM) designs because multiple observations are taken over a long period of time within a design structure of replication and/or randomization of the conditions of the experiment.
When to use ATDs?
ATDs are ideally used with behaviors emitted at a relatively high frequency that correspondingly allows many instances of each alternate intervention to be applied. However, the design may be used with relatively infrequent behaviors if data is collected for a longer period of time.
What works clearinghouse?
The What Works Clearinghouse (WWC) Procedures and Standards Handbook (version 3.0) provides reviewers with a detailed description of the procedures and standards used by the WWC in the review of studies and production of reports. While the Handbook addresses most situations, reviewers occasionally need additional guidance. The WWC has produced a series of guidance documents for reviewers to provide clarification and interpretation of standards and support consistency across reviews. These guidance documents do not articulate any changes to the procedures and standards in the version 3.0 Handbook. Rather, the guidance documents clarify how the standards should be implemented in situations where the current Handbook is not sufficiently specific to ensure consistent reviews.
What is a phase change in a reversal withdrawal design?
Each baseline/intervention change or criterion change should be considered a phase change. As such, there should be at least three different criterion changes to establish three attempts to demonstrate an intervention effect. In some studies using this design, the researcher may reverse or change the criterion back to a prior level to further establish that the change in criterion was responsible for the outcomes observed on the dependent variable. This should be considered a phase change, as in the reversal-withdrawal design.
What is a changing criterion design?
The WWC Procedures and Standards Handbook (version 2.1) noted that the changing criterion design is a variant of a reversal-withdrawal (or ABAB) design , “In this design the researcher examines the outcome measure to determine if it covaries with changing criteria that are scheduled in a series of predetermined steps within the experiment. An A phase is followed by a series of B phases (e.g., B1, B2, B3…BT), with the Bs implemented with criterion levels set for specified changes. Changes/differences in the outcome measure(s) are assessed by comparing the series associated with the changing criteria.” (pp. 65–66). This section provides additional guidance for evaluating changing criterion designs under the version 3.0 Pilot Single-Case Design Standards described in Appendix E of the WWC Procedures and Standards Handbook (version 3.0).
What is a single case interventionist?
In single-case designs, teachers, parents, or peers (collectively labeled interventionists) can administer the intervention to study participants. When study participants experience a different interventionist across baseline and intervention phases of the study, the study has a potential confounding factor. This section provides additional guidance for the identification of confounding factors in single-case designs.
What is MC adjustment in a WWC?
As described in the Procedures and Standards Handbook (version 3.0), pp. 25–26 and Appendix G, the WWC applies a multiple comparison (MC) adjustment “to account for multiple comparisons or ‘multiplicity,’ which can lead to inflated estimates of the statistical significance of findings.” (p. 25). A WWC review may report on multiple outcomes in a single domain for a number of reasons, as explained below. The MC adjustment that the WWC applies is to correct for the lens used in the WWC review of particular contrasts in a study, which is not necessarily all of the contrasts presented in a study. The only time that the WWC needs to apply an MC adjustment is when there are a number of contrasts, subgroups, and/or outcomes within a domain that are reported in a study that meet standards and are included in the WWC’s presentation of the findings.
What is the WWC standard and procedure?
The WWC Standards and Procedures Handbook (version 3.0) provides a list of acceptable statistical methods to account for missing data, focusing primarily on missing outcomes in low-attrition RCTs (pp. 18–19). While these methods can be used for missing baseline variables, equivalence cannot be demonstrated using imputed data. This section provides more guidance on missing data approaches for low-attrition RCTs and other study designs.
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Abstract
In this article, we respond to Wolery’s critique of the What Works Clearinghouse (WWC) pilot Standards, which were developed by the current authors. We do so to provide additional information and clarify some points previously summarized in this journal.
What works Clearinghouse?
The What Works Clearinghouse (WWC) single-case design technical documentation provides an excellent overview of appropriate SC study analysis techniques to evaluate the effectiveness of intervention effects. 1, 18 First, visual analyses are recommended to determine whether there is a functional relationship between the intervention and the outcome. Second, if evidence for a functional effect is present, the visual analysis is supplemented with quantitative analysis methods evaluating the magnitude of the intervention effect. Third, effect sizes are combined across cases to estimate overall average intervention effects, which contribute to evidence-based practice, theory, and future applications. 2, 18
What are quality appraisal tools?
Quality appraisal tools are important to guide researchers in designing strong experiments and conducting high-quality systematic reviews of the literature. Unfortunately, quality assessment tools for SC studies are relatively novel, ratings across tools demonstrate variability, and there is currently no “gold standard” tool. 56 Table 2 lists important SC study quality appraisal criteria compiled from the most common scales; when planning studies or reviewing the literature, we recommend readers to consider these criteria. Table 3 lists some commonly used SC quality assessment and reporting tools and references to resources where the tools can be located.
What is the purpose of 2 level modeling?
Two-level modeling to estimate the intervention effects across cases can be used to evaluate across-case effect sizes. 44, 45, 50 Multilevel modeling is recommended by the WWC standards because it takes the hierarchical nature of SC studies into account: measurements are nested within cases and cases, in turn, are nested within studies. By conducting a multilevel analysis, important research questions can be addressed (which cannot be answered by single-level analysis of SC study data), such as (1) What is the magnitude of the average treatment effect across cases? (2) What is the magnitude and direction of the case-specific intervention effect? (3) How much does the treatment effect vary within cases and across cases? (4) Does a case and/or study-level predictor influence the treatment's effect? The 2-level model has been validated in previous research using extensive simulation studies. 45, 46, 51 The 2-level model appears to have sufficient power (>0.80) to detect large treatment effects in at least 6 participants with 6 measurements. 21