A Visual Aid and Objective Rule Encompassing the Data Features of Visual Analysis

Abstract

Visual analysis of single-case research is commonly described as a gold standard, but it is often unreliable. Thus, an objective tool for applying visual analysis is necessary, as an alternative to the Conservative Dual Criterion, which presents some drawbacks. The proposed free webbased tool enables assessing change in trend and level between two adjacent phases, while taking data variability into account. The application of the tool results in (a) a dichotomous decision regarding the presence or absence of an immediate effect, a progressive or delayed effect, or an overall effect and (b) a quantification of overlap. The proposal is evaluated by applying it to both real and simulated data, obtaining favorable results. The visual aid and the objective rules are expected to make visual analysis more consistent, but they are not intended as a substitute for the analysts' judgment, as a formal test of statistical significance, or as a tool for assessing social validity.

How Many Tiers Do We Need? Type I Errors and Power in Multiple Baseline Designs

“…Second, our study limited its analysis to the dual-criteria method and visual inspection. In the future, researchers may also explore other methods of data analyses to examine whether the results remain consistent (e.g., Krueger et al, 2013, Manolov & Vannest, 2020. Third, our analyses only involved simulated data as it is impossible to measure power on nonsimulated data without delving into circular reasoning.…”

“…The most studied structured visual aids in single-case research are the dual-criteria and conservative dual-criteria methods (Fisher et al, 2003). Several researchers have shown that these methods adequately control for errors of analyses in single-case AB designs (Falligant et al, 2020;Lanovaz et al, 2017;Manolov & Vannest, 2020). To apply the dual-criteria method, the researcher or practitioner must first draw the baseline (i.e., Phase A) data mean and trend lines.…”

“…For single-case research, decision on the effect of the independent variable primarily relies on visual inspection of graphs, which is also recommended by the WWC guidelines (Kratochwill et al, 2010(Kratochwill et al, , 2013. Although visual inspection remains a subjective practice (Manolov & Vannest, 2020;Ninci et al, 2015;Wolfe et al, 2018), the Type I error rate and the power of visual inspection are largely undocumented. As such, one may argue that visual inspection could be more powerful than the dual-criteria method and circumvent the issues observed in the first study.…”

Machine Learning to Analyze Single-Case Data: A Replication and Extension

“…Several studies have questioned the reliability of visual analysis for identifying behavior changes on single-case graphs (DeProspero & Cohen, 1979;Ninci et al, 2015;Wolfe et al, 2016Wolfe et al, , 2018. To address this issue, researchers have proposed different methods to more objectively analyze single-case data (Fisher et al, 2003;Krueger et al, 2013;Lanovaz et al, 2020;Manolov & Vannest, 2020). Notably, Fisher et al (2003) developed the dual-criteria and conservative dual-criteria methods, which have been the topic of a growing number of studies examining their validity (Falligant et al, 2020;Lanovaz et al, 2017Lanovaz et al, , 2020Wolfe et al, 2018).…”

“…While researchers have shown that these methods may adequately control Type I error rates (e.g. Falligant et al, 2020;Lanovaz et al, 2017), studies have also noted that their power could benefit from improvements (Fisher et al, 2003;Manolov & Vannest, 2020).…”