The multiple baseline design is useful for interventions that are irreversible due to learning effects, and when treatment cant be withdrawn. Concurrent and nonconcurrent multiple baseline designs address maturation in virtually identical ways through both within- and across-tier comparisons. Journal of Behavioral Education, 13(4), 213226. Describe the retrospective and prospective research designs. If we observe a potential treatment effect in one tier and corresponding changes in untreated tiers after similar amounts of time (i.e., number of days), maturation becomes a more plausible alternative explanation of the initial potential treatment effect. On the other hand, if we observe that one tier shows a change whereas other tiers that have been observed for similar amounts of time do not show similar changes, this may reduce the plausibility of the maturation threat. On the other hand, across-tier comparisons may be strengthened by arranging tiers to be as similar as possible so that they would be more likely to be exposed to the same coincidental events. A functional relation can be inferred if the pattern of data demonstrates experimental controlthe experimenters ability to produce a change in the dependent variable in a precise and reliable fashion (Sidman, 1960). This is a preview of subscription content, access via your institution. If a potential treatment effect is seen in one tier and on the same day there is no change in other tiers, this is taken as strong evidence that the potential treatment effect was not a result of a coincidental event, because a coincidental event would have had an effect on all tiers. WebNew Mexico's Flagship University | The University of New Mexico 234235). A multiple baseline design with tiers conducted at different times during each day could show disruption due to this coincidental event in the tier assessed early in the day but not in tiers that are assessed later in the day. chapter 9 Flashcards | Quizlet Single-case designs for educational research. This would align the definition with the critical features required to demonstrate experimental control and thereby allow strong causal statements based on multiple baseline designs. Behavior Research Methods, 43(4), 971980. Therefore, concurrent and nonconcurrent designs are virtually identical in control for testing and session experience. An example of multiple baseline across behaviors might be to use feedback to develop a comprehensive exercise program that involves stretching, aerobic exercise, PubMed Any of these types of circumstances may require additional tiers in order to clearly address threats to internal validity. After implementing the treatment for the first tier, they say, rather than reversing the just produced change, he instead applies the experimental variable to one of the other as yet unchanged responses. https://doi.org/10.1002/bin.191, Article The across-tier comparison is valuable primarily when it suggests the presence of a threat by showing a change in an untreated tier at approximately the same time (i.e., days, sessions, or dates) as a potential treatment effect. We will focus on the three types of threats that are addressed through comparisons between baseline and treatment phases in multiple baseline designs: maturation, testing and session experience, and coincidental events.Footnote 1. Application of multiple baseline designs in behavior analytic research: Evidence for the influence of new guidelines. We examine how these comparisons address maturation, testing and session experience, and coincidental events. So, for example, session 10 in tier 2 must take place at some time between tier 1s session 9 and 11. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. As we argued above, the observation of no change in an untreated tier is not strong evidence against a coincidental event affecting the treated tier. If session experience exerted a small degree of influence on the DV, an effect might be observed in settings where the behavior is more likely, but not in settings where the behavior is less likely. A potential treatment effect in any single tier could plausibly be explained as a result of a coincidental event. https://doi.org/10.4324/9781315537085. Both concurrent and nonconcurrent multiple baseline designs also afford the same across-tier comparison; both can show a potentialtreatment effect after a certain number of baseline sessions in one tier and a lack of effect after that same number of sessions in another tier. WebMultiple-Baseline Designs There are two potential problems with the reversal designboth of which have to do with the removal of the treatment. Barlow, D. H., Nock, M. K., & Hersen, M. (2009). Having identified the criticisms of nonconcurrent multiple baseline designs, we now turn to a detailed analysis of threats to internal validity and features that can control these threats. Psychological Methods, 17(4), 510550. In the end, judgments about the plausibility of threats and number of tiers needed must be made by researchers, editors, and critical readers of research. Watson and Workman (1981) noted that the requirement that observations be taken concurrently clearly poses problems for researchers in applied settings (e.g., schools, mental health centers), since clients with the same target behavior may only infrequently be referred at the same point in time (p. 257). Each replication requires an assumption of a separate event coinciding with a distinct phase change. A broad and general impression such as these designs are relatively strong is not sufficient to guide experimental design decisions or to evaluate particular variations of multiple baseline designs. National Center for Biotechnology Information Additional replications further reduce the plausibility of extraneous variables causing change at approximately the same time that the independent variable is applied to each tier. Maturation refers to extraneous variables such physical growth, physiological changes, typical interactions with social and physical environments, academic instruction, and behavior management procedures that tend to cause changes in behavior over time (cf., Shadish et al., 2002). WebOften creates lots of problems BAB Reversal Design Doesnt enable assessment of effects prior to the intervention May get sequence effects May be appropriate with dangerous behaviors Addresses ethics of withholding effective treatment Need to be careful when using NCR Reversal Technique Noncontingent reversal This comparison may reveal a likely maturation effect. The multiple baseline family of designs includes multiple baseline and multiple probe designs. Single case experimental designs: Strategies for studying behavior change (3rd ed.). Timothy A. Slocum. The authors argue that like the concurrent multiple baseline design, the nonconcurrent form can rule out coincidental events (i.e., history) as a threat to internal validity and that experimental control can be established by the replication of the within-tier comparison with phase changes offset relative to the beginning of baseline. These observations lead us to the conclusion that neither of the critical assumptions that coincidental events will (1) contact and (2) have similar impact on all tiers can be assumed to be valid. This information would allow readers to evaluate the sufficiency of each dimension of lag given the specific characteristics of the particular study. (1973). Peer reviewers and editors who serve as gatekeepers for the scientific literature must also have a deep understanding of these issues so that they can distinguish between stronger and weaker research, ensure that information critical to evaluating internal validity is included in research reports, and assess the appropriateness of discussion and interpretation of results. Multiple baseline and multiple probe designs. Anyone you share the following link with will be able to read this content: Sorry, a shareable link is not currently available for this article. Smith (2012) found that SCD was reported in 143 different journals that span a variety of fields such as behavior analysis, psychology, education, speech, and pain management; across these fields, multiple baselines account for 69% of SCDs. Experimental and quasi-experimental designs of research. Basic Books. Likewise, setting-level coincidental events are those that contact a single setting. Controlling for maturation requires baseline phases of distinctly different temporal durations (i.e., number of days); controlling for testing and session experience requires baseline phases of substantially different number of sessions; and controlling for coincidental events requires phase changes on sufficiently offset calendar dates. Further, for the across-tier comparison to detect the influence of a coincidental event, that event must not only contact multiple tiers, it must cause similar changes in the dependent measure across multiple tiers. Elapsed time does not directly cause maturational changes in behavior. Characteristics of single-case designs used to assess intervention effects in 2008. https://doi.org/10.1037/a0029312, Watson, P. J., & Workman, E. A. 7. Multiple baseline designs can rigorously control these threats to internal validity. Multiple baseline designs are the workhorses of single-case design (SCD) research and are the predominant design used in modern applied behavior analytic research (Coon & Rapp, 2018; Cooper et al., 2020). Neither the within-tier comparison, nor the across-tier comparison depends on the tiers being conducted simultaneously; both types of comparisons only require that phase changes occur after substantially different amounts of time since the beginning of baselinethat is, each tier is exposed to different amounts of maturation (i.e., days) prior to the phase change. Other design features that contribute to the isolation of tiers such that any single extraneous variable is unlikely to contact multiple tiers can also strengthen the independence of tiers. They state, the nonconcurrent multiple baseline across participants design is inherently weaker than other multiple baseline design variations. Part of Springer Nature. For example, Gast et al. Google Scholar. Harvey, M. T., May, M. E., & Kennedy, C. H. (2004). . Any alternative explanation of this pattern of results would have to posit an alternative set of causes that could plausibly result in changes in the dependent variable in this specific pattern across the multiple tiers. They then describe the multiple baseline technique (p. 94) and two types of comparisons that contribute to its experimental control. Shadish, W. R., Cook, T. D., & Campbell, D. T. (2002). WebMULTIPLE BASELINE DESIGN Most widely used for evaluating treatment effects in ABA Highly flexible Do not have to withdraw treatment variable Is an alternative to reversal To answer the first question, the one must distinguish signal (systematic change) from noise (unsystematic variance). Behavioral Assessment, 7(2), 129132. Such events might be said to contact all tiers, but affect only one of them. The concurrent multiple baseline design opened up many new opportunities to conduct applied research in contexts that were not amenable to other SCDs. Throughout their discussion of SCD, these authors describe experimental control in terms of three processes: prediction, verification, and replication. (2020) make a somewhat different methodological criticism of nonconcurrent multiple baseline designs. Perspect Behav Sci 45, 619638 (2022). Watson and Workman described a nonconcurrent multiple baseline design in which participants could be begin a study as they became known to the researcher. However, this kind of support is not necessary: lagged replications of baseline predictions being contradicted by data in the treatment phase provide strong control for all of these threats to internal validity. https://doi.org/10.1023/B:JOBE.0000044735.51022.5d, Hayes, S. C. (1981). Type I errors and power in multiple baseline designs. With stable data, the range within which future data points will fall is They describe the control afforded by the design: The experimenter is assured that his treatment variable is effective when a change in rate appears after its application while the rate of concurrent (untreated) behaviors remains relatively constant (p. 226). Threats to Internal Validity in Multiple-Baseline Design Variations. Three children (ages 4;3 to 5;3) with moderate-severe to severe SSDs participated in two cycles of therapy. This consensus is that nonconcurrent multiple baseline designs are substantially weaker than concurrent designs (e.g., Cooper et al., 2020; Johnston et al., 2020; Kazdin, 2021). Google Scholar. In both forms of multiple baseline designs, a potential treatment effect in the first tier would be vulnerable to the threat that the changes in data could be a result of testing or session experience. Oxford. Campbell, D. T., & Stanley, J. C. (1963). Testing and session exposure may be particularly troublesome in a study that requires taking the participant to an unusual location and exposing them to unusual assessment situations in order to obtain baseline data. Rosales-Ruiz, J., & Baer, D. M. (1997). To understand the ability of concurrent designs to meet these assumptions we must distinguish different types of coincidental events based on the scope of their effects. WebDisadvantages to Multiple Baseline Designs -Weaker method of showing experimental control than a reversal (b/c no withdrawal of treatment) -Delay in treatment can occur as For example, it is implausible that the effects of maturation would coincide with a phase change after 5 days in one tier, after 10 days in a second tier, and after 15 days in a third. WebLike RCTs, the multiple baseline design can demonstrate that a change in behavior has occurred, the change is a result of the intervention, and the change is significant. In a review of the SCD literature, Shadish and Sullivan (2011) found multiple baseline designs making up 79% of the SCD literature (54% multiple baseline alone, 25% mixed/combined designs). Correspondence to must have stable baseline and tx in first bx Although the claims that nonconcurrent multiple baseline designs are weaker than concurrent multiple baselines, especially with respect to threats of coincidental events, are nearly universal in the current literature, none of these authors acknowledge or address, the arguments made by Watson and Workman (1981) and Hayes (1981) in support of these designs. Data from the treatment phase in one tier can be compared to corresponding baseline data in another tier. Hersen and Barlows (1976) textbook appears to be the first complete description of the multiple baseline design with many of the ideas about experimental control that are current to this day. An alternative explanation would have to suggest, for example, that in one tier, experience with 5 baseline sessions produced an effect coincident with the phase change; in a second tier, 10 baseline sessions had this effect, again coinciding with the phase change; and in a third tier, 15 baseline sessions produced this kind of change and happened to correlate with the phase change. This is consistent with the judgements made by numerous existing standards and recommendations (e.g., Gast et al., 2018; Horner et al., 2005; Kazdin, 2021; Kratochwill et al., 2013). Natural multiple baselines across persons: A reply to Harris and Jenson. Use the Previous and Next buttons to navigate the slides or the slide controller buttons at the end to navigate through each slide. Although the design entails two of the three elements of baseline logicprediction and replicationthe absence of concurrent baseline measures precludes the verification of [the prediction]. Single-case experimental designs: Strategies for studying behavior change. This certainty is increased by isolation of tiers in time and other dimensions. However, each replication of the possible treatment effect that takes place at a substantially distinct calendar date reduces the plausibility of this threat. Three phonological patterns were targeted for each child. When changes in data occur immediately after the phase change, are large in magnitude, and are consistent across tiers, threats to internal validity tend to be less plausible explanations of the data patterns, and fewer tiers would be required to rule them out. The Family of Single-Case Experimental Designs This paper describes procedures for using these designs, Journal of Consulting & Clinical Psychology, 49(2), 193211. Journal of Behavioral Education, 13(4), 267276. In this design, behavior is measured across either multiple individuals, behaviors, or settings. The withdrawal phase of an A-B-A design is important because it shows that the results of the intervention weren't just a result of a difference in time. The vast majority of contemporary published multiple baseline designs describe the timing of phases in terms of sessions rather than days or dates. Third, patterns of results influence the number of tiers needed to yield definitive conclusions. Consequently, it is often difficult or impossible to dismiss rival hypotheses or explanations. Third, we explore how concurrent and nonconcurrent multiple baselines address each of the main threats to internal validity. When he turned to multiple baseline designs, Hayes argued that AB designs are natural to clinic work and that forming a multiple baseline can consist of collecting several AB replications, which would inevitably have differing lengths of baseline (i.e., a nonconcurrent multiple baseline; p. 206). Slider with three articles shown per slide. A : true B : false. Still, for a given study, the results influence the number to tiers required in a rigorous multiple baseline design. In such an instance, there may be a disruption to experimental control in only one-tier of the design and not others, thus influencing the degree of internal Webmultiple baseline (3 forms) 1. across bx 2. across settings, 3. across subjects or groups using 3-5 tiers. Given this dilemma, priority should be given to optimizing the within-tier comparisons because this is the comparison that can confer stronger control. In order to meet the terms of the definition, and confirm the critical characteristics for controlling threats to internal validity, we recommend that all multiple baseline studies explicitly report, for each tier, the number of days and sessions in each phase, and the number of calendar days of phase change lag from the previous tier. Addressing the second question requires data analysis that is informed by the specifics of the study. Although the across-tier comparison may detect some coincidental events; it cannot be assumed to detect them all. Threats to Internal Validity in Multiple-Baseline Design Effects of instructional set and experimenter influence on observer reliability. Poor execution can certainly worsen these problems, but good execution cannot eliminate them. The current SCD methodological literature and most SCD textbooks claim that because the tiers of nonconcurrent multiple baseline are not synchronized in real time they have a diminished capacity to control for extraneous variables, in particular coincidental events (e.g., Carr, 2005; Gast et al., 2018; Harvey et al., 2004; Johnston et al., 2020). These events would contact all tiers of a MB that take place in that single setting, but not tiers in other settings. Tactics of scientific research. The time lag must be sufficiently long so that no single event could produce potential treatment effects in more than one tier. For both types of comparisons, addressing maturation begins with an AB contrast in a single tier. Recognizing these three dimensions of lag has implications for reporting multiple baseline designs. In the current study, it is likely that exposure to some of the measures can affect scores on other measures or repeated exposure to a measure can lead to socially desirable responding or 2023 Springer Nature Switzerland AG. Threats to Internal Validity in Multiple-Baseline Design Variations, https://doi.org/10.1007/s40614-022-00326-1, Concurrence on Nonconcurrence in Multiple-Baseline Designs: A Commentary on Slocum et al. We have no known conflict of interest to disclose. However, ina concurrent multiple baseline across settings a setting-level event would contact only a single tierthe design would be inherently insensitive to these coincidental events. The Nonconcurrent Multiple-Baseline Design: It is What it