An alternative method for quantitative synthesis of single-subject researches: percentage of data points exceeding the median.

The purpose of the present study is twofold: (a) to compare the validation of percentage of nonoverlapping data approach and percentage of data points exceeding the median of baseline phase (PEM) approach, and (b) to demonstrate application of the PEM approach in conducting a quantitative synthesis of single-subject research investigating the effectiveness of self-control. The results show that the PEM had higher Spearman correlation with original authors' judgment than PND did. The results of applying the PEM approach to synthesize the effect of self-control training on academic and social behavior showed that the treatment was highly or at least moderately effective.