Visual analysis and nonoverlap-based effect sizes are predominantly used in analyzing single case experimental designs (SCEDs). Although they are popular analytical methods for SCEDs, they have certain limitations. In this study, a new effect size calculation model for SCEDs, named performance criteria-based effect size (PCES), is proposed considering the limitations of four nonoverlap-based effect size measures, widely accepted in the literature and blend well with visual analysis. In the field test of PCES, actual data from published studies were utilized, and the relationship between PCES, visual analysis, and the four nonoverlap-based methods was examined. In determining the data to be used in the field test, 1,012 tiers (AB phases) were identified from four journals, which have the highest frequency of SCEDs studies, published between 2015 and 2019. The findings revealed a weak or moderate relationship between PCES and nonoverlap-based methods due to its focus on performance criteria. Although PCES has some weaknesses, it promises to eliminate the causes that may create issues in nonoverlap-based methods, using quantitative data to determine socially significant changes in behavior and complement visual analysis.